Kinematics
Starting from rest, an object accelerates on a straight level surface at a rate of 2 m/s2 for 10 seconds. What is the speed of the object at the end of 10 seconds?
20 m/s
What is the magnitude of the force of gravity on a 10kg object?
100 N
Without looking at your equation sheet, the equation for kinetic energy is...
K=1/2mv2
What does in-elastic mean?
Objects stick together
What direction does centripetal acceleration always point?
towards the center of the circular path
A ball is thrown upward from the ground with an initial speed of 25 m/s; at the same instant, another ball is dropped from a building 15 m high. After how long will the balls be at the same height?
0.6s
What is the magnitude of the normal force on a 250 g whiteboard marker at rest on the table?
2.5 N
What type of energy is associated with the relative positions of objects in a system?
potential energy
Which type of collision is energy conserved?
Elastic
A merry-go-round is accelerated uniformly from rest to an angular velocity of 5 rad/s in a period of 10s. How many times does the merry-go-round make a complete revolution in this time?
4 complete revolutions
An object starts from rest at t=0s. The velocity v(t) is given by v=2t+3t2. How far does the object travel in the first 5 seconds?
150m
What is the coefficient of friction between a rough surface at a 45 degree incline and a 4 kg book at rest?
mu = 1
When is the total mechanical energy of a system conserved? I. Always II. When nonconservative forces are present but do not do work. III. When nonconservative forces are not present.
II. and III.
On what does the direction of an object's momentum depend?
The direction of its velocity
A car, starting from rest, accelerates for 5 seconds until its wheels are moving with an angular velocity of 1000 rad/s. What is the angular acceleration of the wheels during this 5 seconds?
200 rad/s2
An object moving in a straight line has a velocity v in m/s that varies with time t in seconds, according to the following function: v=8t+2.5t3 What is the instantaneous acceleration at t=2s?
38 m/s2
Consider a 5 kg object at rest on a 30 degree incline. What is the normal force of the ramp on the object?
43.3 N
A 2 kg mass is moving in one dimension with a velocity given by v(t)=1/2t2. At t=4s, the instantaneous power delivered by the net force is...
P = 64 watts
In what circumstances is momentum not conserved?
When a net external force acts on a system
An object movies in a circle of radius 2 m with an instantaneous angular velocity of 5 rad/s and an angular acceleration of 4 rad/s2. What's the magnitude of the centripetal acceleration of the object?
50 m/s2
The acceleration of a moving object is a=9t2. The object has an initial position of -2 m and is travelling with a velocity of 3 m/s in the negative x direction. At what time is the acceleration of the object 38 m/s/s?
2.05s
The equation for the velocity of a 2kg particle as a function of time is v(t)=30t3 + 10. Derive an expression for the net force on the particle as a function of time.
F(t)=180t2
A 10 kg mass is moving at 5 m/s over a rough surface. A 50 N horizontal tension force causes it to accelerate to 8 m/s while travelling 6 m. The coefficient of kinetic friction between the mass and the surface is...
= 0.18
What is the mass of a disk of radius 10 m which requires 15 Nm of torque to change its rotational velocity by 20 rad/s in 30 s?
2.25*10-3 kg