Forces Review

1. Forces Review

2. Which of the following is the cause of an acceleration or a change in an object’s motion? • speed • inertia • force • velocity

3. Which of the following forces is an example of a field force? • gravitational force • frictional force • normal force • tension

4. A cart is pushed with an acceleration of 2 m/s2. If µ = 0.5, what does the net force equal? • FA • FFr • FA – FN • FA – FFr • 0

5. An army ranger is lifted by a cable to a helicopter at a constant velocity? • FT • Fg • FT– Fg • Fg– FT • 0

6. A bike is coasting to a stop. What is the net force equal to? • Gravitational Force • Zero • Frictional Force • Normal Force

7. Which of the following is the tendency of an object to maintain its state of motion? • acceleration • inertia • force • velocity

8. An object with a mass of 100kg has what weight in Newtons? • 9.8 • 980 • 0 • 500

9. With a constant applied force, mass is directly proportional to acceleration. This statement describes which of Newton’s Laws? • 1st • 2nd • 3rd • None of the above

10. If a nonzero net force is acting on an object, then the object is definitely • at rest. • moving with a constant velocity. • being accelerated. • losing mass.

11. Which are simultaneously equal but opposite forces resulting from the interaction of two objects? • net external forces • field forces • gravitational forces • action-reaction pairs

12. What is not true regarding action reaction forces? • They are an application of Newton’s 3rd Law. • They act on the same object. • They act on different objects. • All are true.

13. The magnitude of the force of gravity acting on an object is • frictional force. • weight. • inertia. • mass.

14. In the terminology “a 500-N block”, the 500-N refers most specifically to the block's: • mass. • force. • weight. • None of the above.

15. It is generally easier to overcome friction when an object is moving than at rest because … • µk is greater than µs • µs is greater than µk • Fgincreases when an object moves • Fgdecreases when an object moves

16. As a car coasts on a level road yet slows down, the net force acting on the tires is: • greater than the normal force times the coefficient of static friction. • equal to the normal force times the coefficient of static friction. • the normal force times the coefficient of kinetic friction. • zero.

17. If an object changes its direction of motion: • the mass of the object had to change. • the inertia of the object had to change. • the speed of the object stays the same. • a force must have been applied to the object.

18. If no forces are acting on an object, its motion will: • continue in the same direction with the same speed. • slow down and eventually stop. • continue at the same speed but could change direction. • continue in the same direction but could change speed.

19. If the net force is negative and the speed is positive: • the speed will decrease over time. • the speed will increase over time. • the speed will stay the same. • the speed will immediately drop to zero.

20. Which of the following will not change as you increase the slope of a ramp? • Normal Force • Fgx • coefficient of friction • Fgy

21. Which of the following about an object on a ramp will increase if you decrease the slope of a ramp? • Frictional Force • Gravitational Force • Fgx • Coefficient of Friction

22. What happens to the normal force as the angle of a ramp increases? • Normal force increases • Normal force decreases • Normal force remains constant

23. What happens to the coefficient of friction as the angle of a ramp increases? • µ increases • µ decreases • µ remains constant

24. The gravitational force on an object is 98N. What is the object’s mass in kg? • 98 • 9.8 • 980 • 10

25. A 1000kg car is at rest on a slope of angle 10o. What equals the normal force? • Fg • Fgsin10 • Fgcos10 • Fgtan10 • FFr

26. A 1000kg car is at rest on a slope of angle 10o. What equals the frictional force? • Fg • Fgsin10 • Fgcos10 • Fgtan10 • FFr