An object moving in a circle at a steady speed has
a. constant linear momentum
b. constant angular momentum
c. constant velocity
d. constant acceleration
[Ques. 2] A watt is equal to
a. 746 horsepower
b. one calorie
c. one joule
d. 1 J/s
e. a unit of energy
[Ques. 3] About how many 100W light bulbs would you have to light up to use energy at the rate of one horsepower?
a. one or two
b. seven or eight
c. the question doesn't make sensehp and W are unrelated
d. dozens
e. none of the above
[Ques. 4] About how many 100W light bulbs would you have to light up to use energy at the rate of one horsepower?
a. one or two
b. seven or eight
c. the question doesn't make sensehp and W are unrelated
d. dozens
e. none of the above
[Ques. 5] After an elastic collision of two balls, the kinetic energies of the two balls are measured to be 12J and 24J. What can be said about the kinetic energy of the two balls before the collision?
a. nothingnot enough information is given
b. the balls had the same energies, 12J and 24J respectively
c. the total kinetic energy of the two balls was 36J
d. none of the above
[Ques. 6] A person runs up a long flight of stairs in 10 seconds. If the person's weight is 600 N and the vertical height of the stairs is 20 meters, the person's power output is
a. 0
b. 3 W
c. 30 W
d. 1,200 W
e. 12,000 W
[Ques. 7] A 2 kg car moving towards the right at 4 m/s collides head on with an 8 kg car moving towards the left at 2 m/s, and they stick together. After the collision, the velocity of the combined bodies is
a. 0
b. 0.8 m/s towards the right
c. 0.8 m/s towards the left
d. 2.4 m/s towards the right
e. 2.4 m/s towards the left
[Ques. 8] Which of the following quantities are conserved in an isolated system?
a. mass c. momentum
b. energy d. all of the above
[Ques. 9] Using a lever to move a rock reduces the force a person must exert. What does it do to the work the person must do?
a. it reduces the work also c. the work increases
b. the work stays the same d. none of the above
[Ques. 10] If one were told the object's initial velocity then one could calculate the work done by using the equations for constant acceleration to find the distance traveled. When we say work is done against a force, we mean the force does
a. none of the work c. negative work
b. positive work d. zero work
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