A catapult consists of a rubber band attached to a handle. A student uses the catapult to fire a ball towards a target. Fig. 4.1 shows the catapult just before the student releases the rubber band.
rubber band
-ball
handle
Fig. 4.1
(a) When the student releases the rubber band, the ball moves towards the target.
Complete the following sentences about energy transfers during this process. Use words
from the box. You may use each word once, more than once or not at all.
elastic
force
friction
gravitational
kinetic
thermal
(0) As the rubber band is pulled back, the work done is transferred into .. elastic
potential energy
[1]
(ii) When the student releases the rubber band, the ball moves forward horizontally. Stored
potential energy is transferred into kinetic
energy. [2]
(III) As the ball travels through the air there is friction with air molecules. This causes some of
the ball's
energy to be transferred into
energy.
[2]​