15, forces and matter

Question 1

what is the equation for force, spring constant and extension?

Answer 1

F = kx

force applied (N) = spring constant (Nm^-1) x extension (m)

Question 2

what is the equation for work done, spring constant and extension?

Answer 2

work done = 1/2 kx^2

work done = 1/2 x spring constant (Nm^-1) x extension^2 (m)

Question 3

what is the equation for pressure, force and area?

Answer 3

pressure = force / area

Question 4

what is the equation for mass, density and volume?

Answer 4

mass = density x volume

Question 5

what is the equation for the pressure due to a volume of liquid?

Answer 5

height x density of liquid x gravity

Question 6

how can a shock absorber with magnets that slide inside a coil when a motorcycle goes over a bump provide electrical energy?

Answer 6

the relative motion from the bump generates voltage

Question 7

explain how pumping water into and out of a buoyancy tank affects the depth of a submarine below the surface?

Answer 7

upthrust acts on the submarine in the water.
upthrust and weight act in opposite directions.
upthrust is equal to the weight of the water displaced.
volume of the submarine is fixed so upthrust is constant.
increasing and decreasing the volume of water increases and decreases the weight but does not affect upthrust.
if weight increases and weight > upthrust then there is a resultant downwards force so the submarine sinks and vice versa.

Question 8

what is an experiment for the hypothesis “increasing the pressure of a fixed mass of gas decreases the volume”?

Answer 8

put weight on the plunger to increase the pressure. use the syringe to measure the volume. calculate pressure from weight/area. compare the increase in pressure to volume of air.