Newton’s Second Law Problems
1. Calculate the acceleration of a 100 kg cart when the net force on it is 50 N.
2. Calculate the horizontal force needed to make a 1.5 kg hockey puck accelerate at 1000 m/s2.
3. What is the acceleration given to a 50 kg block of cement when it is pulled sideways with a net force of
800 N?
4. Heather can apply a force of 72 N to a wagon in which sits her little brother, Bryce. The combined mass of
Bryce and the wagon is 48 kg. If starting from rest, how much speed will the wagon pick up after Heather
has pushed the wagon for 3.0 s?
5. A golf ball leaves the tee at a speed of 170 mph (75 m/s). If the ball has a mass of 0.05 kg and gains this
speed in 0.02 s, what is the force of impact of the club on the ball?
6. A 500 kg subcompact car and a 1500 kg standard care are given equal accelerations. How many times
greater is the force that acts on the more massive car?
7. An astronaut of mass 90 kg walks in space outside her spaceship and receives a 30 N force from a nitrogen
spurt gun. What acceleration does she experience?
8. If the astronaut was initially at rest, how fast will she be moving after 2.0 seconds?
9. A 2000 kg pickup truck is moving at a speed of 40 m/s as its brakes are applied and comes to a stop in 10
s. What was the braking force applied to the truck?
10. Calculate the acceleration of a 2000 kg single-engine airplane just before takeoff when the thrust of its
engine is 500 N.
11. Calculate the acceleration of a 300,000 kg jumbo jet just before takeoff when the thrust for EACH of its
four engines is 30,000N.
12. A certain force applies to a 2 kg mass accelerates the mass at 3 m/s2. How much acceleration will the
same force produce on a 4 kg mass?
13. If a person weighs 750 N on Earth, what is
their mass?
14. What is the weight of a 68 kg astronaut on
Earth?
15. What is the 68 kg astronaut’s weight on the
moon where g = 1.6 m/s2?
16. What is “g” on a planet where an astronaut
of m = 75 kg has a weight of 550 N?
20. A rocket is propelled upward by the thrust force
of its engines. The thrust force is 10,000 N. The
mass of the rocket is 950 kg.
A. Draw a free body diagram of the forces.
B. Calculate the weight of the rocket.
C. What is the NET force acting on the rocket?
D. What is the acceleration of the rocket?
20 N
30 N
m = 2 kg
17. What is the NET force? What is the
acceleration?
21. A crane is lowering a window washing
platform from the top of a building with a cable.
The platform has a mass of 270 kg, and the
tension in the cable is 2200 N.
A. Draw a free body diagram of all the forces
acting on the platform.
5N
7N
B. Calculate the weight of the platform.
m = 3 kg
4N
18. What is the NET force? What is the
acceleration?
4N
m = 5 kg
6N
2N
19. What is the NET force? What is the
acceleration?
C. What is the NET force acting on the platform?
D. What is the acceleration of the platform?