Forces and their effect

Question 1

Explain why Cylinder A sinks further in the sand than Cylinder B

Answer 1

• gas cylinders have the same weight
• but cylinder A has the smallest area that is in contact with the ground
• the smaller the area, the greater the force
• so cylinder A exerts greater pressure on the ground

Question 2

The bubbles of a gas rise to the surface.

The temperature of the gas does not change

Explain what happens to a bubble as it rises to the surface

Answer 2

• bubbles get bigger
• molecules of gas in constant motion
• molecules widely spread and move randomly
• molecules impact on surface of bubble molecules
• average of impacts produces gas pressure
• pressure due to rate at which gas particles collide
• liquid pressure decreases as bubble rises
• if pressure decreases volume of bubble will increase
• as volume increases, rate at which particles collide with the surface of bubble decreases

Question 3

How far did Sam travel during 15s?

Answer 3

D - 150m

Question 4

At which of these times is the resultant force on joe bigger

Answer 4

B - at 7s

Question 5

Explain why Joe finds it easier to accelerate

Answer 5

• mass is less

- more acceleration from the same force

Question 6

Truck

the resultant force on the car is

Answer 6

A - 0N

Question 7

Discuss whether this rope could be strong enough to tow the car with the truck

Answer 7

• the rope doesn’t have to support the weight of the car
• tension caused by accelerating force
• forces could be kept below 12,000 if acceleration is kept low

Question 8

Force P

Force Q

Answer 8

B -

Force P : reaction
Force Q: friction.

Question 9

Explain whether he does more total work if he walks up the same stairs instead of running

Answer 9

• work done is the same for walking and running

- because work done depends on force and distance only not time