A dog playing fetch starts at rest and accelerates at 4.5m/s2 north. It takes the dog 7 seconds to catch the ball. What was the speed of the dog when he caught the ball?
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
How will the electrostatic force between two electric charges change if the first charge is doubled and the second charge is only one third of the original charge?
A) 4/9
B) 2/3
C) 6 times
D) 2/9
Answer:
B) [tex]\frac{2}{3}[/tex]
Explanation:
The electric force between charges can be determined by;
F = [tex]\frac{kq_{1} q_{2} }{r^{2} }[/tex]
Where: F is the force, k is the Coulomb's constant, [tex]q_{1}[/tex] is the value of the first charge, [tex]q_{2}[/tex] is the value of the second charge, r is the distance between the centers of the charges.
Let the original charge be represented by q, so that;
[tex]q_{1}[/tex] = 2q
[tex]q_{2}[/tex] = [tex]\frac{q}{3}[/tex]
So that,
F = [tex]q_{1}[/tex][tex]q_{2}[/tex] x [tex]\frac{k}{r^{2} }[/tex]
= 2q x [tex]\frac{q}{3}[/tex] x [tex]\frac{k}{r^{2} }[/tex]
= [tex]\frac{2q^{2} }{3}[/tex] x [tex]\frac{k}{r^{2} }[/tex]
= [tex]\frac{2}{3}[/tex] x [tex]\frac{kq}{r^{2} }[/tex]
F = [tex]\frac{2}{3}[/tex] x [tex]\frac{kq}{r^{2} }[/tex]
The electric force between the given charges would change by [tex]\frac{2}{3}[/tex].
Estimate the volume of each ball. Use the formula
where V is the volume and r is the radius. Record the volumes in Table A of your Student Guide.
What is the estimated volume of the table tennis ball?
cm3
What is the estimated volume of the golf ball?
cm3
The given question is incomplete. The complete question is:
Estimate the volume of each ball. Use the formula [tex]v=\frac{4\pi\times r^3}{3}[/tex] where v is the volume and r is the radius. record the volume in table A of your student guide. The radius of the tennis ball is 2.1 cm and the radius of thr golf ball is 2.0 cm. What is the estimated volume of the table tennis ball in [tex]cm^3 [/tex] What is the estimated volume of the golf ball in
Answer: Volume of the tennis ball is [tex]38.8cm^3[/tex] and Volume of the golf ball is [tex]33.5cm^3[/tex]
Explanation:
We have to find the Volume of tennis ball and golf ball by using the formula [tex]v=\frac{4\pi\times r^3}{3}[/tex]
Radius of the tennis ball = 2.1 cm
Radius of the golf ball =2.0 cm.
Putting the value of radius in the formula , we get:
Volume of the tennis ball = [tex]\frac{4\times 3.14\times (2.1cm)^3}{3} =38.8cm^3[/tex]
Volume of the golf ball = [tex]\frac{4\times 3.14\times (2.0cm)^3}{3} =33.5cm^3[/tex]
Volume of the tennis ball is [tex]38.8cm^3[/tex] and Volume of the golf ball is [tex]33.5cm^3[/tex]
it's 38.8 and 33.5 hope this helps
A 55 kg person falling with a velocity of 0.6
Answer:
What are we supposed to find, if it is kinetic energy then this is the solution.
K.E=1/2mv^2
K.E= kinetic energy
M=mass
V=velocity
K.E =0.5*55*0.6^2
K.E=9.9J
Explanation:
A wave has frequency of 50 Hz and a wavelength of 10 m. What is the speed of the wave? Group of answer choices
Explanation:
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PLEASE HELP ME
Find the work done by a man who is pulling a box of 45kg of mass by means of rope which makes angle of 45 degrees.
Answer:
0
Explanation:
No work is done by the man since we do not know the distance or displacement.
Work is only said to be done when the force applied on an object moves it through a particular distance.
Work done = Force x distance.
Since no distance is given in this problem, we can as well assume that the force applied is doing no work on the object.
Question 2
3 pts
If a car is traveling at 32 m/s and has a mass of 2,413, how much
Kinetic Energy does it have? (Round to the nearest tenth)
Answer:
1235.5J
Explanation:
Given parameters:
Mass of car = 2413kg
Speed of car = 32m/s
Unknown:
Amount of kinetic energy it has = ?
Solution:
Kinetic energy is the energy due to the motion of a body;
Kinetic energy = [tex]\frac{1}{2}[/tex] m v²
m is the mass
v is the velocity
Now insert the parameters;
Kinetic energy = [tex]\frac{1}{2}[/tex] x 2413 x 32² = 1235.5J
(97-R) Dos cargas puntuales iguales están separadas por una distancia d. A) ¿Es nulo el campo eléctrico total en algún punto? Si es así, ¿cuál es la posición de dicho punto? B) Repita el apartado anterior suponiendo que las cargas fueran de distinto signo.
Answer:
Explanation:
El campo eléctrico provocado por una carga puntal sobre determinado punto viene dado por la ecuación:
E = K * Q /r² en esa ecuación E es el campo eléctrico (un vector), K es una constante K = 1/4*π*ε₀ Q es la carga que origina el campo, y r la distancia entre la carga y el punto donde se quiere determinar el campo. La fuerza de origen eléctrico y el campo eléctrico van en la dirección de la recta de unión entre carga y punto ( es decir según r) y esta fuerza sera repulsiva o de atracción según que la carga que la origina sea positiva o negativa (respectivamente, ya que en la determinación de fuerza y campo, se asume que se coloca una carga de prueba positiva en el punto ).
Siendo así, si dos cargas elécticas son iguales y están separadas una distancia r ; en el punto medio (r/2) los campos producidos por cada una de las cargas serán de la misma magntud.
Carga Q₁ = Carga Q₂ = Q
E₁ = K * Q₁ / (r/2)² y E₂ = K * Q₂/(r/2)²
Y además tendran direcciones totalmente opuestas, por lo que se anularan
En el segundo caso las cargas son iguales en magntud pero de diferentes signos ( una positiva y la otra negativa ). En este caso los campos eléctricos continuaran siendo de la msma magnitud pero dado que la carga positiva repele la carga de muestra (teorica) y la negativa la atrae los dos campos coinciden en su dirección y resultará una campo de magnitud doble. La dirección del campo será en la tendencia de acercarse a la caga negativa, así si la carga negativa está a la derecha la fuerza de origen eléctrico y el campo van hacia la derecha y si la carga negativa está a la izquierda pues esa será la diercción del campo
What is the same about a particle as gas, liquid, or solid?
A. The speed at which the particles move.
B. The volume that the substance takes up.
C. The chemical composition.
D. The temperature of the substance.
The thing same about a particle as gas, liquid, or solid is its chemical composition.
What are states of matter?
Matter exists in three different states: solid, liquid, and gas. By examining the configuration of their particles, it is possible to understand why they have various qualities. Theoretically, at this temperature, particles move slowly and have the least amount of energy.
Phase refers to the material's actual state. To pay attention to is the word physical. Only physical means can change the state of matter. You can make a physical change if energy is added (by raising the temperature) or subtracted (by freezing things).
The chemical composition of matter same about a particle as gas, liquid or solid.
To learn more about states of matter refer to the link:
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A ball of mass 0.3kg, moving at a velocity of 20m/s is suddenly hit by a force of 5N for a time of 0.03 sec. Find its new velocity of motion
Answer:
F * t = m * Δv
F * t = m * (v2 - v1) where v2 is the new velocity and v1 is the current velocity
m * (v2 - v1) = (F * t)
Plugging in the values,
0.3kg * v2 - 0.3kg * 20 m/s = 5 * 0.03 s
0.3 * v2 - 6 = 0.15
0.3 * v2 = 0.15 + 6
v2 = 6.15 / 0.3
v2 = 20.5 m/s
The new velocity of motion is 20.5 m/s.
A 445-N force is used to hold up a Papa Johns sign in place. What is the mass of the sign?
Answer:
The mass of the sign is 44.5 kg.
Explanation:
Given that,
Force acting on the sign, F = 445 N
We need to find the mass of the sign.
Net force acting on it is given by :
F = mg
Where g is the acceleration due to gravity
[tex]m=\dfrac{F}{g}\\\\m=\dfrac{445\ N}{10\ m/s^2}\\\\m=44.5\ kg[/tex]
So, the mass of the sign is 44.5 kg.
what should be angle between force and displacement to get the minimum work
Answer:
90°
Explanation:
This angle is the measured between the force applied and the displacement where the force vector and the displacement vector are on opposite direction.
The formula for work in this case is ;
W=F*d* cos ∅ where ;
F= force, d= distance and ∅ is the work angle
For minimum work ∅ = 90°
For maximum work ∅ = 0°
An amusement park ride consists of a rotating
circular platform 11.4 m in diameter from
which 10 kg seats are suspended at the end
of 1.54 m massless chains. When the system
rotates, the chains make an angle of 32.3
◦ with the vertical.
The acceleration of gravity is 9.8 m/s
What is the speed of each seat?
Answer in units of m/s.
012 (part 2 of 2)
If a child of mass 29.2 kg sits in a seat, what is
the tension in the chain (for the same angle)?
Answer in units of N.
Answer:
1.54
Explanation:
Is work being done on a barbell when a weight lifter is holding the barbell
over his head?
Answer:
Because in order for work to be done on an object, the object must be moving. Why isn't work being done on a barbell when a weight lifter is holding the barbell over his head? Work is maximized when force is applied in the same direction that the object is moving. ... In order to do work faster, more_is required.
what kind of earthquake related technologies are engineers and scientists working on currently?
Answer:
Technologies such as seismographs, creepmeters, and laser beams are used to detect seismic events.
Explanation:
Which of these characteristics would best help a student who is focused on reaching academic goals?
Creativity
Responsibility
Love
Acceptance
Answer:
B. responsibility
Explanation:
2. A uniform rod of weight 5N and length 1m is pivoted at a point 20cm from one of its ends. A weight is hung from the other end so that the rod balances horizontally. What is the value of the weight?
Answer:
The weight is 7.5 N
Explanation:
Since the rod is uniform, its weight applies downwards at its middle (i.e 50 cm mark). The diagram attached to this answer shows the appropriate sketch.
Applying the principle of moment to the question, let the weight by represented by W.
Total clockwise moment = Total counterclockwise moment
[tex]F_{1}[/tex] x [tex]d_{1}[/tex] = [tex]F_{2}[/tex] x [tex]d_{2}[/tex]
5 x 0.3 = W x 0.2
1.5 = 0.2 W
W = [tex]\frac{1.5}{0.2}[/tex]
= 7.5 N
The value of the weight is 7.5 N.
3. A bee flies forward at 4.9 for 33 s, lands on a flower and stays there for 7s, then flies back along its previous route at 1.9 for 39 s. What is the average speed of the bee
during the entire time?
O 1.701
O 3.001
O 4.466
O 3.801
None of these is correct.
Answer:
None of these is correct.
Explanation:
The average speed can be derived from the sum of the total distance traveled and the total time taken.
Total distance = 4.9 + 1.9 = 6.8
Total time taken = 33 + 39 = 72
So;
Average speed = [tex]\frac{total distance}{total time}[/tex] = [tex]\frac{6.8}{72}[/tex] = 0.014
None of the answer choices given is correct.
An object moves with constant velocity .
•1st law
•2nd law
Answer:
An object moves with constant velocity .
Explanation:
•2nd law
3. A man hits a 0.2 kg golf ball with a force of 4
N. at what rate will the golf ball
accelerate?
Answer:
Force(f)= mass x acceleration
Acceleration (a) is the rate of change in velocity.
F=4N
M=0.2kg
a=F/M
a=4/0.2
a=20m/s^2
Explanation:
Answer:
the answer would be 20 m/s^2
Explanation:
Which event is best demonstrated with the model below? plate plate Formation of a mid -ocean ridge An earthquake A volcanic eruption Formation of a mountain
URGENT
Is it
A
B
C
Or D
A: formation of mid ocean ridge
B: an earthquake
C: a volcanic eruption
D: formation of a mountain
Answer:
d i think
Explanation:
becuse
Answer:
B
Explanation:
What is health literacy?
Health literacy is knowing about health and knowledge of of right healthcare and services, taking care of diseases or just knowledge or taking care of your own health.
An artificial satellite orbits Earth at a speed of 7800 m/s and a height of 200 km above Earth’s surface. The satellite experiences an acceleration due to gravity of
A39 m/s2
Bless than 39 m/s2 but greater than 9.8 m/s2
C9.8 m/s2
Dless than 9.8 m/s2 but greater than zero
Answer: less than 9.8 m/s^2 but greater then zero
Explanation:
Gravitation law
The gravitational acceleration experienced by the satellite is 9.26m/s².
Therefore, Option D) less than 9.8 m/s2 but greater than zero is the correct answer.
Given the data in the question;
Speed or Velocity of the artificial satellite; [tex]v = 7800m/s[/tex]Height of satellite above the Earth; [tex]h = 200km = 200000m[/tex]
To keep the satellite in orbit, a centripetal force is required, this is provided by the gravitational force.
Hence, [tex]F_{centripetal } = F_{gravity}[/tex]
That is; [tex]\frac{mv^2}{r} = mg[/tex]
divide both sides by "m"
[tex]\frac{v^2}{r} = g[/tex]
Here, v is the velocity, g is the gravitational acceleration experienced by the satellite, r is the distance of the satellite from the center of the EARTH.
Diameter of the Earth; [tex]D_{Earth} = 12742 km = 12742000m[/tex]
Radius of the Earth; [tex]R_{Earth} = \frac{12742000m}{2} = 6371000m[/tex]
So,
Distance of the satellite from the center of the EARTH; [tex]r = R_{Earth} + h = 6371000m + 200000m = 6571000m[/tex]
Now we substitute our values into the equation
[tex]\frac{v^2}{r} = g[/tex]
[tex]g = \frac{(7800m/s)^2}{6571000m} \\\\g = \frac{60840000m^2/s^2}{6571000m}\\\\g = 9.26m/s^2[/tex]
The gravitational acceleration experienced by the satellite is 9.26m/s².
Therefore, Option D) less than 9.8 m/s2 but greater than zero is the correct answer.
Learn more; https://brainly.com/question/7282772
Write the equation for Newton's law of universal gravitation
Answer:
This was done by measuring the acceleration due to gravity as accurately as possible and then calculating the mass of Earth M from the relationship Newton's universal law of gravitation gives mg=GmMr2 m g = G m M r 2 , where m is the mass of the object, M is the mass of Earth, and r is the distance .
which unit would be most
suitable for its scale?
Answer:
down below
Explanation:
for a scale, kg is used, as well as grams
for force, newtons is used
A 76g ball is attached to a string that is 1.5m long. It is spun so that it completes two full rotations every second. What is the centripetal acceleration felt by the ball? m/s2
What is the Force tension on the string? N
The centripetal acceleration = 236.63 m/s²
The force = 17.98 N
Further explanationGiven
mass = 76 g = 0.076 kg
r = 1.5 m
f = 2 rps = 2 rotation per second
Required
The centripetal acceleration
The Force tension
Solution
Centripetal force is a force acting on objects that move in a circle in the direction toward the center of the circle
[tex]\large {\boxed {\bold {F = \frac {mv ^ 2} {R}}}[/tex]
F = centripetal force, N
m = mass, Kg
v = linear velocity, m / s
r = radius, m
The speed that is in the direction of the circle is called linear velocity
Can be formulated:
[tex]\tt \displaysyle v = 2 \pi.r.f[/tex]
r = circle radius
f = rotation per second (RPS)
The linear velocity : 2 x 3.14 x 1.5 x 2 =18.84 m/s
The centripetal acceleration : ac = v²/R = 236.63 m/s²
The force : F = m x ac = 0.076 x 236.63 = 17.98 N
What is the working principle of an electric motor?
a) Electromagnetic induction.
b) An electric current flowing through a matallic wire produces magnetic
field.
c) Relative motion of a coil in a magnetic field produces electric current.
d) A current carrying wire experiences a force in a magnetic field.
A complete description of your _____ includes a distance, direction, and reference point. This includes an object's distance in a certain direction from a reference point.
Answer:
Position.
Explanation:
Motion can be defined as a change in location with respect to a reference point.
This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.
Mathematically, the motion of an object is described in terms of acceleration, time, distance, speed, velocity, displacement etc.
A complete description of your position includes a distance, direction, and reference point. Thus, this includes an object's distance in a certain direction from a reference point.
Help, please! Thank you for your kind gesture
Answer:
The last option.
Explanation:
Since you are going down, the gravitational potential energy would go down too. Thus, the gravitational potential energy decreases.
Since the gravitational potential energy is converted to kinetic energy when you move down, there is an increase in kinetic energy.
Answer:
The fourth option
Explanation:
A person walks 6.0 miles in 2.5 hours. Calculate the average velocity of the person.
Please show the work and the answer ty.
Answer:
[tex]1.1 \: \mathrm{m/s}[/tex]
Explanation:
The formula for average velocity is [tex]\frac{\Delta x}{\Delta t}[/tex], where [tex]\Delta x[/tex] = total displacement and [tex]\Delta t[/tex] = time.
Because velocity is usually given in meters per second, convert 6.0 miles to meters and 2.5 hours to seconds:
6.0 miles = [tex]9656.09\: \mathrm{meters}[/tex]
2.5 hours = [tex]9000 \: \mathrm{seconds}[/tex]
Therefore the average velocity of the person is [tex]\frac{9656.09}{9000} \approx 1.07 = \fbox{$1.1\: \mathrm{m/s}$}[/tex] (two significant figures).