UPDATE | 100% CORRECT
The gravitational force that earth exerts on an object causes an impulse of
+10times S in one experiment and +1 times S on the same object in another
experiment. How can this be? Answer - B. The time intervals during which the
force was exerted are different
A bullet fired at a door makes a hole in the door but does not open it. Your
finger does not make a hole in the door but does open it. Why? Answer - C. A
finger exerts a smaller force but the time interval is much longer
How would you convince somebody that the momentum of an isolated system
is constant? Answer - E. Both c and d work
- Derive it from Newton second and third laws
-use it to make predictions about a new experiment, and then compare the
outcome to the prediction
A wagon full of medicine balls is rolling along the street. Suddenly one
medicine ball ( 3 kg) falls off the wagon. What happens to the speed of the
wagon? Answer - B. The speed of the wagon does not change
When can you apply the idea that momentum is constant to solve a problem?
Answer - A. When the system is isolated