Forces 2

Question 1

What is friction?

Answer 1

Friction is a force that may impede motion and produce heating.

Question 2

How does drag affect the motion of objects acted on by a constant weight or driving force?

Answer 2

Without drag: The object accelerates uniformly due to the constant driving force.
With drag (e.g., air resistance or liquid resistance): The object experiences reduced acceleration as the drag force opposes motion and increases with speed.

Question 3

How does an object reach terminal velocity?

Answer 3

As an object falls, the drag force (e.g., air resistance) increases with speed.
Eventually, the drag force equals the weight of the object.
At this point, the resultant force is zero, and the object moves at a constant speed called terminal velocity.

Question 4

What is thinking distance?

Answer 4

Thinking distance is the distance a vehicle travels during the driver’s reaction time before applying the brakes.

Question 5

What is braking distance?

Answer 5

Braking distance is the distance a vehicle travels while the brakes are applied until it comes to a complete stop.

Question 6

What is stopping distance?

Answer 6

Stopping distance is the total distance a vehicle travels before it stops, calculated as:

Stopping distance = Thinking distance + Braking distance

Question 7

What factors affect thinking distance?

Answer 7

Speed: Higher speed increases thinking distance.
Tiredness: Reduces reaction time.
Alcohol and drugs: Impair reaction time.

Question 8

What factors affect braking distance?

Answer 8

Speed: Higher speed increases braking distance.
Load: A heavier vehicle takes longer to stop.
Tyre surface: Worn tyres reduce friction.
Road conditions: Wet or icy roads reduce friction.