Download Force Practice Problems Name: Per: ______ Answer the following

Force Practice Problems
Name: ___________________________________________________ Per: _________
Answer the following question (on a separate sheet of paper) to the best of your ability. All work
must be shown for full credit. When force is involved, you must include a FBD.
1. Okay, a small insect smashes into the windshield of your car while you are zooming down
the interstate.
a. Which exerts the larger force; the bug on the car or the car on the bug? How come?
b. Which experiences a larger acceleration; the bug or the car? How come?
2. A 450.kg mass is accelerated at 2.50m/s2.
a. What is the net force causing this acceleration?
b. If the mass of the car is doubled, what happens to the acceleration (prove using math)?
3. How much does a 39.5kg gymnast weigh?
4. A 2510kg car is pushed from rest with a 252N force:
a. What is the acceleration of the car?
b. What is the car’s velocity at the end of 35 seconds?
5. Two forces act on a 60.0 kg mass. One force is pulling the mass in the +x direction with
180.N. The other force is pulling the mass in the –x direction with 210.N.
a. Calculate the NET force acting on the mass.
b. Calculate the NET acceleration of the mass, including direction.
c. If the two forces are applied to the mass (starting at rest) for 5.00 seconds, what would
the final velocity of the mass be (include direction)?
6. Box A (12.5kg) and Box B sit next to each other at rest on a frictionless floor. A girl comes
along and pushes Box A into Box B giving them an acceleration of 1.05m/s2 (why can’t she
just walk past them?!). If Box B pushes Box A with a force of 7.93N:
a. What is the mass of Box B?
b. What force does she push on Box A?
7. A crate rests on very low friction wheels. The crate and the wheels and stuff have a weight
of 865 N. You pull on the rope with a force of 145 N.
a. What is the acceleration of the system?
b. How far will it move in 2.00 s?
8. A small weather rocket weighs 15.7 N.
a. What is the rocket’s mass?
b. The rocket fires its engine when it is dropped from a balloon at high altitude. If the
rocket has a thrust of 109.2 N, what is the acceleration on the rocket?
9. Two masses are connected by a light string that runs over a frictionless
pulley as shown. What is the acceleration of the system when the masses
are released and allowed to move?
2.25 kg
m1
2.10 kg
m2
10. Two of these here masses are connected by a very light weight string that
passes over your basic very low friction pulley. The mass on the left is
3.25kg. The 3.25 kg mass accelerates upward at 0.345 m/s2. What is the
mass on the other side of the pulley?
a
3 .2 5 k g
11. A boy pushes a lawnmower. The handle of the lawn mower makes an angle of 22.0 with
the horizontal. If the boy pushes with a force of 135 N, what are the horizontal and vertical
components of the force?
37.0
12. Find the tension in each cable supporting the 600.0 N cat burglar.
13. A disturbing weight hangs suspended as shown in the
drawing. Find the tensions in the two strings.
20.3
79.0
119 kg
14. A 3.45 g hockey puck rests on a flat, smooth table. A horizontal net force of 85.0 N acts on
it for 1.10 seconds. The puck slides across the table at the end of that time and then falls off
the table. The table’s top surface is 85.0 cm above the deck. Find:
a. The acceleration of the puck
b. The speed of the puck after the 1.10 s
c. The horizontal distance from the table edge to where the puck impacts the deck.
1. Inertia 2. 1130N, 1.25m/s2 3. 387N 4. 0.100m/s2, 3.5m/s 5.-30.0N, -0.500m/s2, -2.5m/s 6.
7.55kg, 21.1N 7. 1.64m/s2, 3.29m 8. 1.60kg, 58.4m/s2 9. 0.339m/s2 10. 3.49kg 11. x=125N,
y=50.6N 12. T1=796N, T2=997N 13&14. ? your turn. 