C1 A spring with its upper end fixed, hangs vertically alongside a metre rule. The
lower end of the spring gave the following readings in Table C1.1 when various
masses were hung from it.
Mass (kg)
Reading (cm)
Applied force (N)
Extension (cm)
0 0.02 0.04 0.06 0.081.00
10.0 12.0 14.0 16.0 17.0 17.5
0
1.0
7.5
(a)
(b)
Table C1.1
State Hooke's law.
Copy and complete the table for the values of applied force (N) and
extension (cm) produced.
Draw a graph of applied force against extension on a graph paper,
[4]
[1]
On the graph, show the elastic limit.
[Total: 10 marks]
(c)
(d)

W= fd
where f is an applied force and d is the distance over which it is applied. when a parachuting skydiver is at constant velocity, he is experiencing "terminal velocity", the point at which his acceleration down is canceled out by air resistance. that means that the resisting force of the air is equal to his weight, but in the opposite direction. with this, we can solve for the work done by the force.
w = fd
w = (92.0)(9.81 m/s^2) (325)
w= 2.93 x 10^5 j
the value for work in this case is positive because it is pushing up on the skydiver, who has a downward force of gravity.
therefore the answer is 2.93 x 10^5 j