Answer:
31.5m/s
Explanation:
Given the following
acceleration a = 4.5m/s²
Time t= 7secs
Required
Final speed v = ?
Using the equation of motion
v = u+at
v = 0+4.5(7)
v = 31.5m/s
Hence the speed of the dog is 31.5m/s
Two charged objects are held 1 meter apart from each other. Then they are moved to 2
meters apart. How is the electrostatic force and gravity force between
them affected by this move?
O
A Gravity will be as strong and the electrostatic force will be strong.
O
B. Both forces will be as strong after the move,
C. Gravity will be as strong and the electrostatic force will be as strong.
OD. Both forces will be as strong after the move.
Answer:
c
Explanation:
mark ma es brainliest
When two charged objects are moved to 2 meters apart from 1 meter. Then, both Gravity and electrostatic forces will be weak.
The electrostatic force and gravity force is inversely proportional to square of distance between two objects.
[tex]F\alpha\frac{1}{r^{2} }[/tex]
Where r is distance between both charged objects.
When two charged objects are moved to 2 meters apart from 1 meter. Then, both Gravity and electrostatic forces will be weak.
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A 2.0kg rock is thrown straight up into the air with a speed of 30m/s. Ignore air resistance. What is the net force acting on the rock?
Answer:
19.6N
Explanation:
Given parameters:
Mass of rock = 2kg
Speed = 30m/s
Unknown:
Net force on the rock = ?
Solution:
The net force acting on this rock is a function of the acceleration due to gravity acting upon it.
Net force = weight = mass x acceleration due to gravity
Net force = 2 x 9.8 = 19.6N downward
Ahhh (∩ڡ∩) peek a boo ∩(︶ڡ︶)∩ Yeah but i need help
Answer:
???
Explanation:
Hydrogen sulfide, H2S, and hydrogen chloride, HCl, are both gases at temperatures above –50 °C.
Which gas will diffuse most rapidly at the temperature given?
A hydrogen chloride at –40°C
B hydrogen chloride at –20°C
C hydrogen sulfide at –40°C
D hydrogen sulfide at –20°C
could someone please explain this
Explanation:
A gas at higher temperature is able to gain more heat from the environment/surroundings and has more kinetic energy to diffuse at a faster rate.
Hence a temperature at -20°C is more ideal.
Molar mass of H2S = 34.07g/mol
Molar mass of HCl = 36.45g/mol
Since H2S has a smaller molar mass, the same number of moles of H2S gas will diffuse faster as compared to the same number of moles of HCl gas.
Hence the answer is Hydrogen sulfide at -20°C. (D)
an object has a mass of 2,000kg. what is its weight on earth? show your work
Answer:
Answer: 19,600 N
Explanation:
Weight is a force, and force equals mass times acceleration. So the formula for weight is w = m • g
How many times greater is the intensity of a 35-db sound compared to a 25-db sound?
Answer:
10 Times (greater)
Explanation:
The given parameters are;
The number of decibels of the first sound, 35-db
The number of decibels of the second sound, 25 db
We have;
[tex]\beta (dB) = 10 \cdot log_{10} \left (\dfrac{I}{I_0 \right)}[/tex]
Where;
I₀ = 10⁻¹² W/m² = The lowest perceivable sound
Therefore, we have;
[tex]I = I_0 \times 10^{\left (\dfrac{\beta }{10} \right) }[/tex]
Substituting the known values, gives;
When β = 35-db, we get;
[tex]I_{35} = 10^{-12} \times 10^{\left (\dfrac{35 }{10} \right) } = 10^{-12} \times 10^{3.5} = 10^{-8.5}[/tex]
When β = 25-db, we get;
[tex]I_{25} = 10^{-12} \times 10^{\left (\dfrac{25 }{10} \right) } = 10^{-12} \times 10^{2.5} = 10^{-9.5}[/tex]
Therefore, we get the number of times the intensity of a 35-db sound is compared to a 25-db sound, which is, I₃₅/I₂₅ is given as follows;
[tex]\dfrac{I_{35}}{I_{25}} = \dfrac{10^{-8.5}}{10^{-9.5}} = 10[/tex]
Therefore, the intensity of a 35-db sound is 10 times greater than the intensity of a 25-db sound
A mover loads a 100 kg box into the back of a moving truck by
pushing it up a ramp. The ramp is 4.0 m long and the back of
the truck is 1.5 m high. The mechanical advantage of the ramp
is
(Round to the nearest tenth)
Check it
Answer:
2.7
Explanation:
The following data were obtained from the question:
Mass (m) of box = 100 Kg
Length (L) of ramp = 4 m
Height (H) of ramp = 1.5 m
Mechanical advantage (MA) of ramp =?
Mechanical advantage of a ramp is simply defined as the ratio of the length of the ramp to the height of the ramp. Mathematically, it is given by:
Mechanical Advantage = Lenght / height
MA= L/H
With the above formula, we can obtain the mechanical advantage of the ramp as follow:
Length (L) of ramp = 4 m
Height (H) of ramp = 1.5 m
Mechanical advantage (MA) of ramp =?
MA = 4/1.5
MA = 2.7
Therefore, the mechanical advantage of the ramp is 2.7
Explain how we perceive objects as they are
pls help, I will mark u as the brainliest
The lens present in our eyes forms a real and inverted image on the retina. The optic nerves carry this image from the retina to the brain. The brain then processes this info to generate clear and virtual images. That's how we perceive objects as they are.
When the image is formed on our "Retina", the light sensitive cells of our Retina gets activated and they generate electric signals. These signals are send to brain by the optic nerves. The brain interprets the electric signals in such a way that we see an image in erect and of the same size as the object... MÅRK ÅS THE ẞRÅÏÑLÏËST.......
White Lake was contaminated with the Chemical Complany dispersing their waste in the lake. Eventually, they were forced to stop dumping it into the lake. using 2-3 sentences, please share what you know about this and if you think the lake is completely cleaned up.
Answer:
White Lake was contaminated with the Chemical Complany dispersing their waste in the lake. Eventually, they were forced to stop dumping it into the lake
Every rock that you find must be or have at one time been a/an
Answer:
crystal
Explanation:
well most rocks are like that
Please help me answer this i really need help!!!
What is different about parasitism compared to the other biological relationships such as mutualism, predation, competition, and commensalism?
Answer: parasitic organisms cause harm to other organisms.
Answer:
parasitic organisms cause harm to other organisms.
Explanation:
6. A hockey player skates ten meters to the goal.
What term is used to describe the hockey
player's process of changing position?
Answer:
Displacement
Explanation:
Displacement is a term used to represent change in position.
if the current is 0.4 A for the 20 ohm resistor, what is the value for the potential difference? ii) Would it be different for the 30 ohm resistor or the same?
Answer:potential difference is more or less like voltage. Using ohms, V=IR
Where V is Voltage
I is Current =0.4A
R is Resistance=20ohms
V=0.4*20
V=8V
Hence the potential difference will be 8V.
ii) V=0.4*30
V=12V
Explanation:
The voltage of potential difference is directly proportional to the current and the resistance. So if one increase or decrease, it will have impact on the other.
From the calculations, when the resistance increase, the voltage will increase to appreciate the change.
Explain why refraction takes place.
Please help explain in a simple way
Answer:
lCdfKFBWRblNLWFNJLBe
Explanation:
jk jk Refraction is an effect that occurs when a light wave, incident at an angle away from the normal, passes a boundary from one medium into another in which there is a change in velocity of the light
Jackson throws a football 30 meters at a speed of 15 m/s. How long was the football in the air before Laurence caught it for touchdown
Answer:
2s
Explanation:
Given parameters:
Distance = 30m
Speed = 15m/s
Unknown:
Time before Laurence caught it = ?
Solution:
To solve this problem;
Speed = [tex]\frac{disance }{time}[/tex]
Time taken = [tex]\frac{distance }{speed }[/tex] = [tex]\frac{30}{15}[/tex] = 2s
The time it takes is 2s
Given:
30 metersSpeed of 15 m/sWe will solve:
Speed = [tex]\frac{distance}{time}[/tex]
Time taken = [tex]\frac{distance}{time}[/tex] = [tex]\frac{30m}{15m/s}[/tex] = 2s
The time it takes is 2s
A 70.0 kg base runner moving at a speed of 4.0 m/s begins his slide into second base. The coefficient of friction between his clothes and Earth is 0.70. His slide lowers his speed to zero just as he reaches the base. How much mechanical energy is lost because of friction acting on the runner? A. 1100 J B. 560 J C. 140 J D. 0J 8. How far does the runner slide? F. 0.29 m G. 0.57 m H. 0.86 m J. 1.2 m
Answer:
B. 560 J
J. 1.2 m
Explanation:
v = Final velocity = 0
u = Initial velocity = 4 m/s
[tex]\mu[/tex] = Coefficient of friction = 0.7
m = Mass of runner = 70 kg
g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]
Kinetic energy is given by
[tex]K=\dfrac{1}{2}m(v^2-u^2)\\\Rightarrow K=\dfrac{1}{2}\times 70\times (0^2-4^2)\\\Rightarrow K=-560\ \text{J}[/tex]
The mechanical energy lost is 560 J
Acceleration is given by
[tex]a=-\mu g\\\Rightarrow a=-0.7\times 9.81\\\Rightarrow a=-6.867\ \text{m/s}^2[/tex]
From kinematic equations we get
[tex]v^2-u^2=2as\\\Rightarrow s=\dfrac{v^2-u^2}{2a}\\\Rightarrow s=\dfrac{0^2-4^2}{2\times -6.867}\\\Rightarrow s=1.165\approx 1.2\ \text{m}[/tex]
The runner slides for 1.2 m
a. The amount of mechanical energy that is lost because of friction acting on the runner is: B. 560 J
b. The distance the runner slide is equal to: J. 1.2 m
Given the following data:
Mass = 70.0 kgSpeed = 4.0 m/sCoefficient of friction = 0.70.Acceleration due to gravity, g = 9.8 [tex]m/s^2[/tex]
a. To determine the amount of mechanical energy that is lost because of friction acting on the runner, we would calculate the change in kinetic energy:
Mathematically, the change in kinetic energy is given by the formula:
[tex]\Delta K.E = \frac{1}{2} m(v-u)^2[/tex]
Substituting the parameters into the formula, we have;
[tex]\Delta K.E = \frac{1}{2} \times 70(4-0)^2\\\\\Delta K.E = 35(4)^2\\\\\Delta K.E = 35 \times 16\\\\\Delta K.E = 560\;Joules[/tex]
Mechanical energy = 560 Joules
b. To determine how far (distance) the runner slide:
First of all, we would find the runner's acceleration.
[tex]Acceleration = ug\\\\Acceleration = 0.70 \times 9.8[/tex]
Acceleration = 6.86 [tex]m/s^2[/tex]
For distance:
[tex]V^2 = U^2 + 2aS\\\\4^2 = 0^2 + 2(6.86)S\\\\16=13.72S\\\\S=\frac{16}{13.72}[/tex]
Distance, S = 1.2 meters.
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The diagram below shows the muzzle of a cannon located 50. meters above the ground. When the cannon is fired, a ball leaves the muzzle with an initial horizontal speed of 250. meters per second. [Neglect air resistance.]Which action would most likely increase the time of flight of a ball fired by the cannon?
Answer:positioning the cannon higher above the ground
Explanation:
❤️
A plane is traveling at a velocity of 90 m/s. It accelerates at a constant rate of 1.5 m/s2 until its velocity reaches 500 m/s. What distance did the plane cover while it was accelerating?
Recall that
v ² - v₀² = 2 a ∆x
where
v₀ = initial velocity
v = final velocity
a = acceleration
∆x = distance
Then
(500 m/s)² - (90 m/s)² = 2 (1.5 m/s²) ∆x
∆x = ((500 m/s)² - (90 m/s)²) / (2 (1.5 m/s²))
∆x ≈ 80,633 m
Imagine you are dating a mineral sample that contains one-eighth of its original parent isotope. What is the
absolute age of the sample if the half-life of the parent isotope is 15 years?
A. 1.875 years
B. 23 years
C. 45 years
D. 120 years
The age of the sample can be determined using the first order equation of the nuclear decay. The age of the parent isotope here is 45 years.
What is half life ?Unstable radioactive nuclei undergo nuclear decay to produce more stable nuclei with more life time. The time required to decay half of the initial amount of a material is called its half life.
The half life of a sample is related with the decay constant k as follows:
k = 0.693/t1/2
Given that, t1/2 = 15 years
k = 0.693/15 = 0.0462 yr⁻¹
The first order equation of the decay process is written as:
k = 1/t ln w0/wt
where w0 is the initial amount and wt be the amount after time t.
then t = 1/k ln w0/wt
Given that, the sample was decayed to one eighth of the initial amount .
t = 1/k ln 8
= 1/0.0462 ln 8
= 45 years.
Therefore, option C is correct.
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what happens if I increase the height of a skater
Answer:
The higher the skater is the more potential energy he has. As his height decreases, his potential energy decreases and his kinetic energy increases.
Explanation:
Make me BRAINLIST please
Answer:
The higher the skater is the more potential energy he has. As his height decreases, his potential energy decreases, and his kinetic energy increases. ... Explore how the skater's change in speed relates to the potential and kinetic energy of the skater.
Explanation:
(Via Uteach)
The two blocks shown below have masses m1 = 400 g and m2 = 600 g. They are connected by a string and lie on a frictionless tabletop. A 3.5 N force is applied to block m2, pulling it to the right. Find the acceleration then find the tension force in the string between two objects
in which diagram 1 or 2 would the person be experiencing summer? explain
Answer:
Diagram 1
Explanation:
In diagram one, the earth is leaning toward the sun, meaning it is summertime.
The person will experience summer in diagram one because the earth is tilted towards the sun.
What is the summer season?From diagram one we can see that earth is tilted towards the sun. During summer, the North Pole of the earth is tilted towards the sun.
As a consequence, the sun’s path is higher in the sky, causing the northern hemisphere to receive more light and heat.
In addition, because the sun is in the sky for more hours, the summer solstice is also the longest day of the year.
These extra hours of sunlight give the sun more time to heat the earth and this is the main reason for summer to be the hottest season.
During summer the sun is perpendicular to the tropic of cancer and heats more areas that lie in the tropic of cancer.
Thus the answer will be diagram 1 because the earth is tilted towards the sun.
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a.) Determine the work done by Zach on the bull.
Explanation:
The unit of work done is in Joules
Work done is a physical quantity that is defined as the force applied to move a body through a particular distance.
Work is only done when the force applied moves a body through a distance.
Work done = Force x distance
The maximum work is done when the force is parallel to the distance direction.
The minimum work is done when the force is at an angle of 90° to the distance direction.
So to solve this problem;
multiply the force applied by Zack and distance through which the bull was pulled.
Jack and Jill decide to run a race. Jack weighs 90 kg and Jill weighs 50 kg. At the end of the race it was decided that Jack and Jill tied so they had the same speed. Which person had more momentum ?
Answer: Jack.
Explanation:
Momentum is defined as the quantity of motion.
For an object that has a mass M, and a velocity V, the momentum is written as:
P = M*V
For this problem, we know that Jack and Jill had the same speed (so they had the same velocity), let's say that this velocity is v.
Then the momentum of Jack will be:
P = 90kg*v
And the momentum of Jill will be:
P = 50kg*v
We can see that Jack will have a larger momentum, and this is because he has a larger mass than Jill, but the same velocity as her.
A car that travels at a velocity of 20 m/s and
has a mass of 1,200 kg.
Answer:
24000kgm/s
Explanation:
Given parameters:
Velocity = 20m/s
mass = 1200kg
Unknown:
Momentum = ?
Solution:
Momentum is the quantity of motion a body possesses.
This is given as:
Momentum = mass x velocity
Momentum = 1200 x 20 = 24000kgm/s
an object has a mass of 2,000kg. what is its weight on earth? show your work
Answer:
F=m*g is the formula and the answer is 19,620 kg
Explanation:
Since the formula is F=m*g and Earth's gravity is 9.81 m/s^2 all you need to do is multiply 2,000 by 9.81
Answer:
[tex]20,000\:\mathrm{N}[/tex]
Explanation:
The weight of an object on Earth is equal to the force of gravity on that object.
We can use the following equation to determine the force of gravity on an object:
[tex]F_g=ma_g=mg[/tex], where [tex]m[/tex] is the mass of the object and [tex]g[/tex] is acceleration due to gravity ([tex]9.81\: \mathrm{m/s}[/tex]).
Solving, we get:[tex]F_g=2,000\cdot9.81=19,620=\fbox{$20,000\:\mathrm{N}$}[/tex] (one significant figure).
Suppose Alex is navigating using a compass. She starts walking at an angle of 60° north of east and walks a total of 100 m. How far north is she from the starting point? How far east?
Answer:
[tex]50\:\mathrm{m\: North}\\50\sqrt{3}\:\mathrm{m\: East}[/tex]
Explanation:
We can create a 30-60-90 triangle. The distance she walked is then the hypotenuse of the triangle, and using 30-60-90 triangle rules, we have the following:
The North leg is opposite to the [tex]30^{\circ}[/tex] angle. Therefore, if we call this distance [tex]y_N[/tex], we have the following:
[tex]\sin 30^{\circ}=\frac{y_N}{100},\\\frac{1}{2}=\frac{y_N}{100},\\y_N=\fbox{$50\:\mathrm{m}$}[/tex].
The East leg is opposite to the [tex]60^{\circ}\\[/tex] angle. If we call this distance [tex]x_E[/tex], we have:
[tex]\sin 60^{\circ}=\frac{x_E}{100},\\\frac{\sqrt{3}}{2}=\frac{x_E}{100},\\x_E=\fbox{$50\sqrt{3}\:\mathrm{m}$}[/tex].
What is the molarity of 2 mol of calcium carbonate, CaCl2, dissolved in 1 L of solution?
HELP PLSS!!!!
Answer:
2mol/L
Explanation:
Given parameters:
Number of moles of calcium carbonate = 2mol
Volume of solution = 1L
Unknown:
Molarity = ?
Solution:
The molarity of a solution is the number of moles of solute dissolved or contained in a solution:
Molarity = [tex]\frac{number of moles }{volume }[/tex]
Molarity = [tex]\frac{2}{1}[/tex] = 2mol/L
A tomado was moving at a velocity of 10 miles/hour north five minutes later the tomado is moving at a rate of 25 miles/hour north. What was the tornado's acclaration?
Answer:
180.7km/hr²
Explanation:
Given parameters:
Initial velocity = 10miles/hr
Final velocity = 25miles/hr
Time taken = 5minutes
To hr
60min = 1hr
5min gives 0.083hr
Unknown:
Acceleration = ?
Solution:
To solve this problem,
Acceleration = [tex]\frac{v - u}{t}[/tex]
v is the final velocity
u is the initial velocity
Acceleration = [tex]\frac{25 - 10}{0.083}[/tex] = 180.7km/hr²