This is a force-extension graph for a spring.

(a) State what is represented by:

(i) The gradient of the graph

This is a force-extension graph for a spring.

(a) State what is represented by:

(ii) The area under the graph.

This is a force-extension graph for a spring.

The spring has force constant $k=80{\mathrm{Nm}}^{-1}$. The spring is compressed by $0.060 \mathrm{m}$, within the limit of proportionality, and placed between two trolleys that run on a friction-free, horizontal track. Each trolley has a mass of $0.40 \mathrm{kg}$. When the spring is released the trolleys fly apart with equal speeds but in opposite directions. How much energy is stored in the spring when it is compressed by $0.060 \mathrm{m}$ ?

This is a force-extension graph for a spring.

(b) The spring has force constant $k=80{\mathrm{Nm}}^{-1}$. The spring is compressed by $0.060 \mathrm{m}$, within the limit of proportionality, and placed between two trolleys that run on a friction-free, horizontal track. Each trolley has a mass of $0.40 \mathrm{kg}$. When the spring is released the trolleys fly apart with equal speeds but in opposite directions.

(ii) Explain why the two trolleys must fly apart with equal speeds.

This is a force-extension graph for a spring.

(b) The spring has force constant $k=80{\mathrm{Nm}}^{-1}$. The spring is compressed by $0.060 \mathrm{m}$, within the limit of proportionality, and placed between two trolleys that run on a friction-free, horizontal track. Each trolley has a mass of $0.40 \mathrm{kg}$. When the spring is released the trolleys fly apart with equal speeds but in opposite directions.

(iii) Calculate the speed of each trolley.

(a) Liquid of density $\rho$ fills a cylinder of base area $\mathrm{A}$ and height $\mathrm{h}$. Using the symbols, state the mass of liquid in the container.

 A boy stands on a platform of area $0.050{ \mathrm{m}}^2$ and a manometer measures the pressure created in a flexible plastic container by the weight $W$ of the boy, as shown.

The density of water is $1000 \mathrm{kg}{ \mathrm{m}}^{-3}$. Determine the pressure difference between the inside of the plastic container and the atmosphere outside

A boy stands on a platform of area $0.050{ \mathrm{m}}^2$ and a manometer measures the pressure created in a flexible plastic container by the weight $W$ of the boy, as shown.

The density of water is $1000 \mathrm{kg}{ \mathrm{m}}^{-3}$. Determine the weight $W$ of the boy.