1) A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates what about the milk carton?

ANSWER: __________________________________________________________

2) An object in mechanical equilibrium is an object (careful - thinking question) Two answers.

ANSWER: ____________________________________	ANSWER: _________________________________

3) When you stand at rest on a pair of bathroom scales, the readings on the scales will always

ANSWER: ____________________________________________

4) Hang from a pair of gym rings and the upward support forces of the rings will always

ANSWER: ___________________________________________

5) A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is

ANSWER: __________ What if the man is on all fours, 2 hands and 2 feet on 4 different scales? ____________

6) The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is

ANSWER: ________________

7) A 200-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is

ANSWER: _________________ How much does the bear weigh in pounds? Hint 2.2 lb./kg ___________

8) A package falls off a truck that is moving at 50 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is

ANSWER: ___________________

9) A truck is moving at constant velocity. Inside the storage compartment of the truck a rock is dropped from the midpoint of the ceiling and strikes the floor below. Where will the rock hit the floor with reference to the ceiling?

ANSWER: ____________________________________

10) If your automobile runs out of fuel while you are driving, the engine stops but you do not come to an abrupt stop. The concept that most explains why It doesn’t stop immediately is:

ANSWER: _____________________________________

11) According to Newton's law of inertia, a railroad train in motion should continue going forever even if its engine is turned off. We never observe this because railroad trains

ANSWER: ________________________________________

12) Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is

ANSWER: to ________________________________________________

13) When a rocket ship accelerating in outer space runs out of fuel, what happens to the rocket’s acceleration?

What happens to the rockets velocity? _________________Why?_______________________________________

What happens to the acceleration? _______________________________

14) If no external forces are acting on a moving object, what happens to the velocity and acceleration?

ANSWER: ______________________________________________________________________________