Forces - terminal velocity and elasticity

Question 1

How does speed affect the friction acting on a car?

Answer 1

the faster an object moves through a fluid, the greater the frictional force that acts on it

Question 2

What happens when an object falls through a fluid (gas or liquid)?

Answer 2

the object will initially accelerate due to the force of gravity

eventually the resultant force will be zero

the object will move at its terminal velocity (steady speed)

Question 3

Why does a parachute reduce the terminal velocity?

Answer 3

parachute increases the surface area of the skydiver, which increases the air resistance

thus decreasing the steady speed (terminal velocity) that the skydiver travels at

Question 4

What can the shape of an object be affected by?

Answer 4

the forces acting on a object

Question 5

What happens when a force is applied to an elastic object?

Answer 5

results in the object stretching and storing elastic potential energy

Question 6

How is a object able to recover its original shape?

Answer 6

elastic potential energy is stored in the object when work is done on the object to change its shape

Question 7

What is the extension of an elastic object directly proportional to?

Answer 7

the force applied

provided that the limit of proportionality is not exceeded

additional guidance:

k is the spring constant in newtons per metre N/m