Answer:
A) v = 28.3 m/s
B) t = 4.64 s
Explanation:
A)
Assuming no other forces acting on the rock, since the accelerarion due to gravity close to the surface to the Earth can be taken as constant, we can use one of the kinematic equations in order to get first the maximum height (over the roof level) that the ball reaches:[tex]v_{f}^{2} - v_{o}^{2} = 2* g* \Delta h (1)[/tex]
Taking into account that at this point, the speed of the rock is just zero, this means vf=0 in (1), so replacing by the givens and solving for Δh, we get:[tex]\Delta h = \frac{-v_{o} ^{2}}{2*g} = \frac{-(17.0m/s)^{2} }{2*(-9.8m/s2)} = 14.8 m (2)[/tex]
So, we can use now the same equation, taking into account that the initial speed is zero (when it starts falling from the maximum height) and that the total vertical displacement is the distance between the roof level and the ground (26.0 m) plus the maximum height that we have just found in (2) , 14.8m:Δh = 26.0 m + 14. 8 m = 40.8 m (3)Replacing now in (1), we can solve for vf, as follows:[tex]v_{f} =\sqrt{2*g*\Delta h} = \sqrt{2*9.8m/s2*40.8m} = 28.3 m/s (4)[/tex]
B)
In order to find the total elapsed from when the rock is thrown until it hits the street, we can divide this time in two parts:1) Time elapsed from the the rock is thrown, until it reaches to its maximum height, when vf =02) Time elapsed from this point until it hits the street, with vo=0.For the first part, we can simply use the definition of acceleration (g in this case), making vf =0, as follows:[tex]v_{f} = v_{o} + a*\Delta t = v_{o} - g*\Delta t = 0 (5)[/tex]
Replacing by the givens in (5) and solving for Δt, we get:[tex]\Delta t = \frac{v_{o}}{g} = \frac{17.0m/s}{9.8m/s2} = 1.74 s (6)[/tex]
For the second part, since we know the total vertical displacement from (3), and that vo = 0 since it starts to fall, we can use the kinematic equation for displacement, as follows:[tex]\Delta h = \frac{1}{2} * g * t^{2} (7)[/tex]
Replacing by the givens and solving for t in (7), we get:[tex]t_{fall} =\sqrt{\frac{2*\Delta h}{g}} = \sqrt{\frac{2*40.8m}{9.8m/s2} } = 2.9 s (8)[/tex]
So, total time is just the sum of (6) and (8):t = 2.9 s + 1.74 s = 4.64 sSolve each of the following problems to 3 sig figs and correct Sl units, showing all work.
1. A cart with a mass of 45.0 kg is being pulled to the right with a force of 250 N giving it an
acceleration of 1.30 m/s2. The wheels of the cart are locked and the cart must be dragged.
a) Draw a free body diagram of the cart.
b) Calculate the net force acting on the cart.
c) Create a force table and fill it in.
d) Find the coefficient of kinetic friction.
Answer:
every number to 3 sf = 1) 45.0 2) 250 3) 1.30
Explanation:
your welcome :)
These three bulbs are powered by the battery. What will happen if the middle light burns out? A. The two other bulbs will go out. B. The two other bulbs will stay on. C. Just the bulb closest to the battery will stay on. D. Just the bulb farthest from the battery will stay on.
Answer:
C
Explanation:
an airplane normally flying at 80 km/h north encounters a wind from the west of 10km/h at right angle to its foward motion a crosswind what will its resultant velocity be ?
Answer:
v = 80.62 km/h
Explanation:
Given that,
An airplane normally flying at 80 km/h north encounters a wind from the west of 10km/h at right angle to its forward motion a crosswind.
We need to find the resultant velocity of the airplane. It can be calculated as follows :
[tex]v=\sqrt{80^2+10^2} \\\\v=80.62\ km/h[/tex]
So, the required velocity is 80.62 km/h.
Sultan walks for 15 km at 35° south of east.
Which of the following journeys would result in the same displacement?
Answer:
☝
Explanation:
A potato with a mass of 0.25kg is resting on a table. Calculate the force that the potato exerts on the Earth.
Answer:
F = 2.45 [N]
Explanation:
The force that the potato exerts on the Earth is equal to the product of the potato mass by gravitational acceleration.
[tex]F=m*g[/tex]
where:
m = mass = 0.25 [kg]
g = gravity acceleration = 9.81 [m/s²]
[tex]F=0.25*9.81\\F=2.45[N][/tex]
treatment for PTSD campus be described A.multumodal multi-phasic b. atheoretical C. stress inclusion D.eclectic
Answer:
Stress inclusion
Explanation:
A type of cognitive behavior therapy for PTSD is pressure inoculation preparation. CBT is a widely used form of antidepressant that can make you know wrong and/or pessimistic emotions that have influenced your actions and alter them.
A person weighs 60kg. Calculate the amount of work done if he is raised 12m into the air.
Answer: I belive the answer would be 720 Joules
Explanation:
Work can be calculated by multiplying an objects weight times the distance traveled. Work is measured in joules (J).
Formula: W x D = J
W= weight
D= Distance
J= joules of energy
Hope it helps
I want you to think about each of these scenarios, what do you think will happen after? I just want you to think about it, and write a little about what is going to happen.
2. A truck is moving at 20 mph. Your car is standing still at a light and the truck crashes into you before the driver has a chance to step on the brakes.
3. You are driving your car at 20 mph. A bicycle right ahead of you suddenly stops and you crash into it before you have a chance to step on the brakes.
4. A bicycle is moving at 20 mph. Your car is stopped for a light and the bicycle crashes into you.
Two spherical objects have masses of 100 kg and 200 kg. Their centers are
separated by a distance of 40 cm. Find the gravitational attraction between
them.
Answer:
8.34 x 10⁻⁶N
Explanation:
Given parameters:
Mass 1 = 100kg
Mass 2 = 200kg
Distance of separation = 40cm = 0.4m
Unknown:
Gravitational force of attraction between them = ?
Solution:
To solve this problem, we use the expression below which is derived from the Newton's law of universal gravitation:
Fg = [tex]\frac{G x mass 1 x mass 2}{d^{2} }[/tex]
G is the universal gravitation constant = 6.67 x 10⁻¹¹
d is the separation
Now;
Fg = [tex]\frac{6.67 x 10^{-11} x 100 x 200}{0.4^{2} }[/tex] = 8.34 x 10⁻⁶N
Plz help this is so confusing
Answer:
5 Km/h
Explanation:
From the question given above, the following data were obtained:
Distance travelled = 10 Km
Time = 2 hours
Speed =?
Speed is simply defined as the distance travelled per unit time. Mathematically, it can be represented as:
Speed = distance travelled /time.
With the above formula, we can obtain the speed at which the duck is travelling as follow:
Distance travelled = 10 Km
Time = 2 hours
Speed =?
Speed = distance travelled /time.
Speed = 10 / 2
Speed = 5 Km/h
Thus, the duck is travelling at a speed of 5 Km/h
What is a path through which electric current can flow through a wire
if we ignore air resistance the mass of an object does not affect the rate at which it accelerate why?
Answer:
See explanation
Explanation:
The acceleration due to gravity on an object is independent of the mass of the object. This is so because, the acceleration due to gravity depends only on the radius of the earth and the mass of the earth.
As a result of this, all objects are accelerated to the same extent and should reach the ground at the same time when released from a height as long as other forces other than gravity are not at work.
A spring stretches by 15cm when a mass of 300g hangs down from it,if the spring is then stretched an additional 10cm and released, calculate;the spring constant,the angular velocity, amplitude of oscillation, maximum velocity, maximum acceleration of the mass,period, frequency
Answer:
0.1 m
Explanation:
It is given that,
Mass of the object, m = 350 g = 0.35 kg
Spring constant of the spring, k = 5.2 N/m
Amplitude of the oscillation, A = 10 cm = 0.1 m
Frequency of a spring mass system is given by :
Time period:
i believe Newton's 1st law is
Answer:
The first law states that if the net force is zero, then the velocity of the object is constant.
A student asks the following question:
"If all things with mass have a gravitational field, why doesn't this glue bottle and
stapler, sitting on the counter, stick together because of gravitational forces?"
Which classmate answers correctly?
Ashton says that the gravitational fields between the bottle and the stapler
cancel out because of Newton's 3rd Law.
O Natalie says that all things with mass have a gravitational field, but the force is
very weak and cannot be perceived around small objects.
Xavier says the bottle and the stapler are way too small to have a gravitational
field.
Katherine says the bottle and the stapler have a strong gravitational field, and
would move towards each other quickly if there were no friction on the counter.
Answer:
Natalie says that all things with mass have a gravitational field, but the force is very weak and cannot be perceived around small objects.
Explanation:
The force due to gravity is proportional to the mass of the object and inversely proportional to the square of the distance between objects. The Earth is so massive that the force due to its gravity is much greater than the force between objects on the counter.
If there were no friction, the objects might move toward each other, depending on what other masses were near them tending to cause them to move in other directions.
Natalie's explanation is about the best.
__
Additional comment
The universal gravitational constant was determined by Henry Cavendish in the late 18th century using lead balls weighing 1.6 pounds and 348 pounds. His experiment was enclosed in a large wooden box to minimize outside effects. While these masses are somewhat greater than those of a glue bottle and stapler, the experiment shows the force of gravity between "small" objects can be measured.
I need this done by tonight!! Can anyone help me please? Answer these 4 questions
Answer:
1. 14 g of chocolate mixture.
2. 24 fl oz of chocolate milk
3. 10 cups of chocolate milk.
4. 12½ cups.
Explanation:
From the question given above, the following data were obtained:
1 TBSP = 7 g
1 Cup = 8 fl oz
2 Table spoons (TBSP) for 1 cup (8 fl oz) of milk.
1. Determination of the mass of chocolate mixture in 1 cup of chocolate milk.
From the question given above,
1 Cup required 2 Table spoons (TBSP)
But
1 TBSP = 7 g
Therefore,
2 TBSP = 2 × 7 = 14 g
Thus, 1 Cup required 14 g of chocolate mixture.
2. Determination of the number fl oz of chocolate milk in 3 cups
1 Cup = 8 fl oz
Therefore,
3 Cups = 3 × 8
3 Cups = 24 fl oz
Thus, 24 fl oz of chocolate milk are in 3 cups.
3. Determination of the number of cups of chocolate milk produce from 20 TBSP.
2 TBSP is required to produce 1 cup.
Therefore,
20 TBSP will produce = 20/2 = 10 Cups.
Thus, 10 cups of chocolate milk produce from 20 TBSP.
4. Determination of the number of cups obtained from 100 fl oz chocolate milk.
8 fl oz is required to produce 1 cup.
Therefore,
100 fl oz will produce = 100 / 8 = 12½ cups.
Thus, 12½ cups is obtained from 100 fl oz chocolate milk.
Two ice skaters stand next to each other on a frozen pond. The first skater has a mass of 65 kg and the
second skater has a mass of 82 kg. If the first skater pushes against the second with a force of 35 N, south, what are their respective
accelerations?
help me !!!
Answer:
D
Explanation:
Given that:
Mass of the first skater = 65kg
Mass of the second skater = 82kg
Force of push = 35N
Unknown:
Their respective accelerations = ?
Solution:
To solve this problem;
Force = mass x acceleration
From Newton's third law of motion, we know that action and reaction are equal and opposite.
So, the force on both Skaters is 35N
Acceleration of first Skater = [tex]\frac{35}{65}[/tex] = 0.54m/s² North
Acceleration of second Skater = [tex]\frac{35}{82}[/tex] = 0.43m/s² South
A teacher places a warm bottles in a cooler filled with ice. Which statement best explains what happened over time?
A) Thermal energy will move from ice to water bottles
B) Coldness will move from the water bottles to the ice.
C) Coldness will move from the ice to the water bottlers
D) Thermal energy will move from the water bottle to the ice.
Answer:
D) Thermal energy will move from the water bottle to the ice.
Explanation:
Overtime, what happens is that thermal energy will move from the water bottle to the ice.
The water bottle is at a higher temperature compared to the ice. So, thermal energy will move from a place at higher temperature to one with lower temperature.
Thermal energy will stop moving until thermal equilibrium is attained. The water bottle will lose heat to the ice and by so doing it becomes colder. The ice will gain heat and begins to warm up
Chocolate milk contains more than one type of component. Therefore, it 1 point
is not a(n)
substance
Answer:
Homogeneous.
Explanation:
Mixture can be defined as a combination of two or more substances present in varied proportion where each materials are distinct and visibly seen by naked eyes.
In Science, there are two (2) main types of mixture and these are;
I. A homogeneous mixture: it can be defined as any liquid, solid or gaseous mixture which has an identical or uniform composition and properties throughout any given sample of the mixture. In Chemistry, all solutions are considered to be a homogeneous mixture. For example, aqueous hydrogen chloride is a homogeneous mixture of water and hydrogen chloride.
II. A heterogenous mixture: it can be defined as any mixture which has a different or non-uniform composition and properties throughout any given sample of the mixture. This ultimately implies that, the constituents of a heterogenous mixture always remain separate in the sample and as such comprises of two or more phases.
Since the chocolate milk contains more than one type of component. Therefore, it is not a homogeneous substance but a heterogenous substance.
There are two different isotopes; X and Y, both contain the same number of radioactive substances. If sample X
has a longer half-life than Y, compare their rate of radioactive decay.
O A. Rate does not depend on half-life
B. Both of their rates are equal
O C. X has a smaller rate than Y
O D. X has a greater rate than Y
Answer:
Half life refers to the time for 1/2 of the radioactive atoms to decay.
Suppose that X has a half life of 10 days and Y has a half life of 20 days
If both start out with 1000 radioactive atoms then after 20 days
X would have 250 radioactive atoms and Y would have 500 atoms
The rate of decay is greater for the shorter half life:
In the example given X must have the smaller rate of decay because it has a longer half life.
calculate the magnitude and the direction of the resultant forces
answer:
resultant = 127.65 in the positive direction
explanation:
F1 = 50N , F2 = 40N, f3 = 55N , f4 = 60N
Fy = 50 sin 50 = 50 × -0.26 = -13
Fx = 40 cos 0 = 40×1 = 40
fx = 55 cos 25 = 55×0.99 = 54.45
Fy = 60 sin 70 = 60 × 0.77 = 46.2
resultant = -13+40+54.45+46.2 = 127.65 in the positive direction
What relationship must exist between an applied force and the velocity of a moving object if uniform circular motion is to result?
Answer:
See explanation
Explanation:
Centripetal force is defined as the inward force required to keep an object moving with a constant speed in a circular path.
The magnitude of this force depends on the mass of the object, radius of the object and the velocity of the body.
So we can write;
F = mv^2/r
find the volume of an object with a density of 3.2 g/mL and a mass of 12 g.
In designing buildings to be erected in an area prone to earthquakes, what relationship should the designer try to achieve between the natural frequency of the building and the typical earthquake frequencies?
A) The natural frequency of the building should be exactly the same as typical earthquake frequencies.
B) The natural frequency of the building should be almost the same as typical earthquake frequencies but slightly lower
C) The natural frequency of the building should be very different frem typical earthquake frequencies
D) The natural frequency of the building should be almost the same as typical earthquake frequencies but slightly higher.
Answer:
C) The natural frequency of the building should be very different from typical earthquake frequencies
Explanation:
We shall apply the concept of resonance in this problem .
When a body is applied an external harmonic force ( forced vibration) such that natural frequency of body is equal to frequency of external force or periodicity of external force , the body vibrates under resonance ie its amplitude of vibration becomes very high .
In the present case if natural frequency of building becomes equal to the earthquake's frequency ( external force ) , the building will start vibrating with maximum amplitude , resulting into quick collapse of the whole building . So to avoid this situation , natural frequency of building should be very different from typical earthquake frequencies .
A ball rolling on the floor eventually comes to a stop. Which statement best describes this situation?
A) The energy on the macroscopic scale and the energy on the molecular scale both decreased.
B) The energy on the macroscopic scale increased, and the energy on the molecular scale decreased.
C) The energy on the macroscopic scale decreased, and the energy on the molecular scale increased.
D) The energy on the macroscopic scale and the energy on the molecular scale both remained constant.
If you have the rest please put them down :)
Answer:
Explanation:
C. The energy on the macroscopic scale decreased, and the energy on the molecular scale increased.
A. friction converts some energy on the macroscopic scale to energy on the molecular scale.
B. The mechanical energy of the system decreased because of friction.
B. The mechanical energy of the system at the beginning of the experiment is equal to the mechanical energy of the system at the end of the experiment.
B. the mechanical energy of the system decreased due to the transfer of energy on a macroscopic scale to energy on a molecular scale.
The ball rolling on the floor eventually comes to a stop which means that
the energy on the macroscopic scale decreased, and the energy on the
molecular scale increased.
What is Macroscopic scale?This is a scale in which an object can be seen with the eyes. When
an object is in motion, the ball rolls away and becomes less visible hence a
decrease in the macroscopic scale.
During motion, friction converts some macroscopic energy into molecular
scale which is why there was an increase in it.
Read more about Macroscopic scale here https://brainly.com/question/17609067
How long ago did most Middle Eastern countries gain their independence?
A.
10-20 years ago
B.
50-100 years ago
C.
200-300 years ago
D.
400-500 years ago
Please select the best answer from the choices provided
A
B
C
D
Answer:
the correct answer is B
Explanation:
Answer:
.B
Explanation:
This is the answer on edge 2021
Have a good day!
Explain whether the acceleration of the moon is higher than,less or equal to that on the earth
Answer:
If we know that [tex]m < M[/tex], then acceleration of the Moon is less to that on the Earth.
Explanation:
From Newton's Law of Gravitation we know that gravitational force between Earth and Moon ([tex]F[/tex]), measured in newtons, is expressed by this formula:
[tex]F = G\cdot \frac{M\cdot m}{r^{2}}[/tex] (1)
Where:
[tex]G[/tex] - Gravitational constant, measured in cubic meters per kilogram-square second.
[tex]M[/tex] - Mass of the Earth, measured in kilograms.
[tex]m[/tex] - Mass of the Moon, measured in kilograms.
[tex]r[/tex] - Distance between centers, measured in meters.
By comparing (1) with definition of Weight, we see that gravitational acceleration experimented by Earth ([tex]g[/tex]), measured in meters per square second, is:
[tex]g = \frac{G\cdot m}{r^{2}}[/tex] (2)
If we know that [tex]m < M[/tex], then acceleration of the Moon is less to that on the Earth.
A 3 kg block is attached to a spring of spring constant k = 250 N/m. The block is pulled to a maximum distance (amplitude) of 8 cm What is the value of the spring force when the block is at 8 cm?
Answer:
20 N
Explanation:
From the question given above, the following data were obtained:
Mass (m) of block = 3 Kg
Spring constant (K) = 250 N/m
Extention (e) = 8 cm
Force (F) =?
Next, we shall convert 8 cm to m. This can be obtained as follow:
100 cm = 1 m
Therefore,
8 cm = 8 cm × 1 m / 100 cm
8 cm = 0.08 m
Thus, 8 cm is equivalent to 0.08 m.
Finally, we shall determine the force when the block is at 8 cm (i.e 0.08 m). This can be obtained as follow:
Spring constant (K) = 250 N/m
Extention (e) = 0.08 m
Force (F) =?
F = Ke
F = 250 × 0.08
F = 20 N
Thus, the force is 20 N.
A 65 kg box is lifted by a person pulling a rope a distance of 15 meters straight up at a constant speed. How much Power is required from the person in order to complete this task in 9 seconds?
__ Watts
Answer:
Power is 1061.67W
Explanation:
Power=force×distance/time
Power=65×9.8×15/9 assuming gravity=9.8m/s²
Power=3185/3=1061.67W
How many joules does your 1600W electric hair dryer transfer if it takes 1 minutes to dry your hair?
____ joules
Answer:
96,000joules!!!
Explanation:
Hope this helps u