Physics Answers

A man pushed a 1,000 kg car to the +x direction. If the applied force is 5000N, what is the acceleration of the the coefficient of the friction force is 0.57

consider a copper of mass 50kg at a temp 10 degree celcius and a copper calorimeter of mass 15kg with water to weigh 4okg. when heat energy is supplied to the calorimeter until the temp reaches 50 degree celcius. find the specific heat capacity of the copper.(given that the s.h.c of water = 4200 and copper = 400) initial temp of calorimeter is 54 degree celcius

1. Several environmental scientists are monitoring the movement of a cheetah on an Ethiopian plain. They find that at t = 5 min, the cheetah is traveling at 5 m/s due west. At t = 15 min, it is moving at 12 m/s toward the west, while at t = 30 min it is moving at 2 m/s toward the east. If we call western movement positive, when is the cheetah’s speed negative? A) During the entire interval from t = 15 to t = 30 min B) Only during part of the interval from t = 15 to t = 30 min C) During at least part of the interval from t = 15 to t = 30 min, and possibly at other times D) Never, since speed is not a vector quantity

A man rides up in an elevator 12 m.He gains 6500 J of potential energy.What is the man's mass?

The principle violated by the following electronic configuration.

1s(2)2s(6)3s(2)

(10%)  Problem 10:   A jet dives vertically at a speed v = 170 m/s, before pulling out of the dive along a circular arc. The pilot can survive an acceleration of a = 8.9 g. His mass is m = 81 kg.

What would be the magnitude of the normal force, in newtons, be at the top of an arc of this radius going the same velocity?

1. Several environmental scientists are monitoring the movement of a cheetah on an Ethiopian plain. They find that at t = 5 min, the cheetah is traveling at 5 m/s due west. At t = 15 min, it is moving at 12 m/s toward the west, while at t = 30 min it is moving at 2 m/s toward the east. If we call western movement positive, when is the cheetah’s speed negative? A) During the entire interval from t = 15 to t = 30 min B) Only during part of the interval from t = 15 to t = 30 min C) During at least part of the interval from t = 15 to t = 30 min, and possibly at other times D) Never, since speed is not a vector quantity

2. If the coefficient of friction between vehicles and the road is 0.4 and the radius of curvature of

a circular curve of the road is 30 m. What is the maximum speed allowable if there is no

banking?

A child is pushing a merry-go-round. The angle through which the merry-go-round has turned varies with time according to θ(t)= γt+ βt³, where γ = 0.400 rad/s and β = 0.0120 rad/s³.

a) Calculate the angular velocity of the merry-go-round as a function of time.

b) What is the initial value of the angular velocity?

c) Calculate the instantaneous value of the angular velocity ω_z at t=0 to t= 5.00 s. Show that the w_av-z is not equal to the average of the instantaneous angular velocities at t=0 and t=5.00 s, and explain why it is not.

A child is pushing a merry-go-round. The angle through which the merry-go-round has turned varies with time according to θ(t)= γt+ βt³, where γ = 0.406 rad/s and β = 1.30×10⁻² rad/s³.

a) Calculate the angular velocity of the merry-go-round as a function of time.

b) What is the initial value of the angular velocity?

c) Calculate the instantaneous value of the angular velocity ω_z at t=0 to t= 5.00 s. Show that the w_av-z is not equal to the average of the instantaneous angular velocities at t=0 and t=5.00 s, and explain why it is not.