Kinematics
Force and Translational Dynamics
Work, Energy, and Power
Momentum
Torque and Rotational Dynamics
100
A stone is thrown horizontally with an initial speed of 10 m/s from a bridge. Assuming that air resistance is negligible, how long would it take the stone to strike the water 80 m below the bridge?
4s
100
A person tries to lift a very heavy 70kg rock by applying an upward force of 500N, but is unable to move it upward. Calculate how much additional force was needed to lift the rock from the ground.
186N
100
What is the equation for work done by a constant force at an angle θ to the displacement?
W = Fdcosθ
100
What is the equation for linear momentum, and what are its units?
p = mv, with units of kg·m/s
100
Terry is pushing a vertical lever that is attached to the floor, and he pushes 1.5m above the point of rotation. If he pushes with a force of 100N at an angle of 60° from the ground, what is the magnitude of torque that he is applying to the lever's hinge?
75Nm
200
How long would it take a car, starting from rest and accelerating uniformly in a straight line at 5 ms-2, to cover a distance of 200m?
9s
200
A person who weighs 700N is standing in an elevator. The elevator then accelerates upward at a rate of 4ms-2. During this acceleration, how much does the person weigh?
986N
200
A 2 kg object falls from a height of 5 m. Ignoring air resistance, how much kinetic energy does it gain just before hitting the ground?
100 J (98 J with g = 9.81)
200
A 0.5 kg ball hits a wall at 10 m/s and bounces straight back at 8 m/s. What is the magnitude of the impulse delivered by the wall?
9 kg·m/s
200
A bolt connecting the main and rear frame of a mountain bike requires a torque of 15Nm to tighten. If you are capable of applying 40N of force to a wrench in any given direction, what is the minimum length of the wrench that will result in the required torque?
0.38m
300
A baseball is thrown straight upward. What is the ball's acceleration at its highest point?
g downward
300
A 10kg block is suspended by two ropes. Each rope makes an angle of 45 degrees to the horizontal.
What is the magnitude of the tension force in each rope?
70.7N
300
Define power and give its SI unit.
Power is the rate at which work is done; the SI unit is the watt (W)
300
What is conserved in an elastic collision but not in an inelastic collision?
Kinetic energy
300
A force F is applied to the edge opposite the doorhinge of a door of radius R perpendicular to the door to produce a torque τ. Suppose now that the force is doubled, but now acts at a point 3R/4 from the doorhinge at an angle of 30∘ to the door. What is the resulting torque in terms of τ?
3τ/4
400
A car travelling at a speed of v0 applies its brakes, skidding to a stop over a distance of x m. Assuming that the deceleration due to the brakes is constant, what would be the skidding distance of the same car if it were traveling with twice the initial speed?
4x m
400
How do you calculate the net force parallel to the slope of a frictionless inclined plane at an angle θ to the horizontal.
mgsinθ
400
A student compresses a spring with spring constant k = 200 N/m by 0.1 m. How much potential energy is stored in the spring?
1 J
400
A 1 kg object moving at 3 m/s collides and sticks to a 2 kg object at rest. What is their final speed?
1 m/s
400
There is a steel disk of radius 1m and uniformly distributed mass 75kg. Assuming that it is perfectly balanced on it's center, determine how much torque would be needed to accelerate it to 2πradians in 2.5s.
Assume I=0.5mr2
94.2Nm
500
A soccer ball, at rest on the ground, is kicked with an initial velocity of 10 m/s at a launch angle of 30°. Calculate its total flight time, assuming that air resistance is negligible.
1s
500
If the force of tension is 25N, the force of static friction is 40N, the block has a mass of 10kg, and the block is motionless, what is the angle A?
40.5°
500
A solid cylinder (mass = 4 kg, radius = 0.2 m) starts from rest and rolls without slipping down a 2 m high incline. What is its speed when it reaches the bottom?
For a solid cylinder: I = (1/2)MR2
5.16 m/s (5.11 m/s with g = 9.81)
500
A figure skater is spinning with her arms extended. As she pulls her arms inward, her moment of inertia decreases. What happens to each of the following quantities? (increases, decreases, or remains the same?)
Angular velocity
Angular momentum
Rotational kinetic energy
Angular velocity: Increases
Angular momentum: Stays the same
Rotational kinetic energy: Increases
500
A uniform rod of length 50cm and mass 0.2kg is placed on a fulcrum at a distance of 40cm from the left end of the rod. At what distance from the left end of the rod should a 0.6kg mass be hung to balance the rod?
45cm