Newton’s Second Law Homework
1. (i) A 5 kg mass is hanging from a string. What is the tension in the string?
2. (i) A 20 gram mass is hanging from a string. What is the tension in the string?
3. (i) A force of 50 N is observed to accelerate a cart at a rate of 4 m/s2. What is the mass of the cart?
4. (i) Calculate the acceleration of a 2000 kg single engine airplane just before takeoff when the thrust of the
engine is 500 N?
5. (i) A force of 650 N is found to be able to accelerate a black box with an acceleration rate of 2.3 m/s2.
What is the mass of the black box?
6. (ii) Wile E. Coyote has a mass of 30 Kg. He has a rocket strapped to his back that has a mass of 10 kg, and
provides 900 N of thrust. What will be the acceleration of the coyote and rocket?
(Questions 7-9) A car with a mass of 1200 kg can accelerate at a rate of 3.6 m/s2.
7. (i) What is the net force required to make this car accelerate like this?
8. (i) One the car reaches a speed of 25 m/s, it stops accelerating. What net force is needed for the car to
maintain this speed?
9. (ii) In a second experiment, the same car with the same engine is observed to only accelerate at a rate of
3.2 m/s2. Approximately how many more people were in this car this time? (Justify your answer).
10. (iii) An electron is 0.001 m away from a stationary positive charge of 2 μC.
a. What will be the acceleration of the electron?
b. Assuming that the electron started from rest, what will be its velocity after 2 seconds?