Ety ratio
by
a. 10? b.10°) c.10-1 d. 10-
3. the work done when a perpendicular force is applied to a body in horizontal motion is
a. 90 j b. 10 j c. maximum d. zero
4. determine the kinetic energy of a girl of mass 40kg running with a velocity of 3 m/s.
a. 150 jb. 180j c. 100
j d . 120 j
5. a ball of mass 0.4kg is dropped from a height of 30m. determine the potential energy
on impact to the ground.
a. 120 j b. 100 j c. 70j d. 102 j
6. gravitational and electric fields are sometimes referred to as conservative force fields
because work done in these fields depends on
a. path b. position c. energy d. strength
7. which of these is an example of non-renewable energy
a. solar b. wind c. coal d. hydro
8. a rocket of mass 40,000kg propelled by a force of 10 n acquires a speed of 3000 m/s
determine the power expended
a. 2 x 10° watts b. 1 x 10° watts c. 4 x 10' watts d. 3 x 10' watts
9. an ideal machine is one with efficiency of
a. 100% b. 0% c. 50% d. 80%
10. if there are 5 pulleys in a block and tackle, then the velocity ratio is
c.6
d. 2
11. an object; constrained to move along the x-axis is acted upon by a force f(x) where
form
ervas
uni:
a. 4
d
b. 5
y