This is a force–extension graph for a spring.

a. State what is represented by:
i. The gradient of the graph
ii. The area under the graph.
b. The spring has force constant k = 80 N m⁻¹. The spring is compressed by 0.060 m, within the limit of proportionality, and placed between two trolleys that run on a friction-free, horizontal track. Each trolley has a mass of 0.40 kg. When the spring is released the trolleys fly apart with equal speeds but in opposite directions.
i. How much energy is stored in the spring when it is compressed by 0.060 m?
ii. Explain why the two trolleys must fly apart with equal speeds.
iii. Calculate the speed of each trolley.

Transcribed Image Text:

Extension Figure 7.23 Force