Physics 7110  Midterm Exam                Name ______________________


1. If a constant non-zero net force is applied to a body, the body  is
a. accelerating
b. moving at constant speed
c. at rest or moving at constant velocity

2. Ball A is dropped from rest as ball B is shot horizontally. The ball that hits the ground first is
a. Ball A
b. Ball B
c. both will hit at the same time

The reason for this is because  

d. ball A has a lesser distance to travel
e. ball B is acted upon by an additional force
f. both balls fall the same vertical distance with equal acceleration

3. If one doubles the speed of a moving body, one also doubles its
a. acceleration
b. momentum
c. kinetic energy
d. potential energy
e. energy

4. A 200 lb skydiver reaches a terminal velocity of about 180 miles per hour and his velocity then stays constant. The air resistance force on him after he reaches terminal velocity is:
a. 180 lbs
b. 200 lbs
c. 20 lbs
d. 380 lbs
e. cant  be determined from data given

5. A projectile is fired horizontally with a speed of 40 m/sec. Air friction is negligible.
a. the horizontal speed will decrease at 9.8 m/s2 because of gravity.
b. the horizontal speed will remain the same during the motion
c. the horizontal speed will increase as it falls.

6. In which case would you have the largest mass of gold? If your chunk of gold weighed 1 newton on the
a. moon
b. Earth
c. planet Jupiter
d. would be the same on each

7. A person is attracted toward the center of the earth by a gravitational force of 500 N. The force with which the earth is attracted toward the person is
a. 500 N
b. infinitesimally small
c. billions and billions of tons

principally because

d. both forces in question make an action/reaction pair
e. the  mass of the person is negligible compared to the mass of the earth
f. the earth itself weighs billions of tons
g. of inertia

8. "Centrifugal force" is an apparent reality to observers in a frame of