Forces And Motion (P1, P2, P3)

Question 1

Define displacement

Answer 1

• Vector quantity

* The direction and distance that an object moves in a straight line from start to finish.

Question 2

Define speed

Answer 2

• Scaler quantity

* Just how fast an object is moving (no direction).

Question 3

Define velocity

Answer 3

• Vector quantity

* How fast an object is moving in a certain direction.

Question 4

What is the speed equation?

Answer 4

Speed = Distance / Time

Question 5

What is the equation for acceleration?

Answer 5

Acceleration = (Final Velocity - Initial Velocity) / Time

OR

Acceleration = Change in Velocity / Time

Question 6

What is the first law of motion?

Answer 6

Balanced forces mean no change in velocity.

Question 7

What is the second law of motion?

Answer 7

A resultant force means acceleration or deceleration.

Question 8

What is the third law of motion?

Answer 8

If an object exerts force onto another object, then that object exerts and equal and opposite force back.

Question 9

What is the force equation?

Answer 9

Force = Mass x Acceleration

Question 10

Define distance

Answer 10

• Scalar quantity

* How far an object moves (no direction)

Question 11

What does gradient measure in DT and VT graphs?

Answer 11

Distance-Time -> Speed

Velocity-Time -> Acceleration

Question 12

What does the area under the graph represent in DT and VT graphs?

Answer 12

Distance-Time -> Nothing

Velocity-Time -> Distance

Question 13

What is the difference between vector and scalar quantities?

Answer 13

Vector -> Have magnitude and direction

Scalar -> Have only magnitude

Question 14

Give some examples of scalar quantities.

Answer 14

Time, Speed, Distance, Mass

Question 15

Give some examples of vector quantities.

Answer 15

Acceleration, Force, Momentum, Weight, GFS

Question 16

What is a resultant force?

Answer 16

A single force that has the same effects as all the forces acting on an object.

Question 17

What happens when the resultant force is zero?

Answer 17

The object remains stationary or travels at a constant velocity.

Question 18

What happens when the resultant force is not zero?

Answer 18

The velocity of the object changes.

Question 19

How does the parallelogram method work?

Answer 19

1. Pick a scale for the forces (e.g. 1N = 2cm)
2. Draw the two forces at the appropriate angle to each other at the correct length according to the scale (e.g. 20N = 10cm)
3. Complete the parallelogram with the other two lines
4. Measure the centre line
5. Convert this to a force using the scale (e.g. 25cm = 12.5N)

Question 20

What two factors increase the FORCE required to stop a car (braking force)?

Answer 20

• Speed of the car

* Mass of the car

Question 21

What is the stopping difference, thinking distance and braking distance?

Answer 21

• Stopping distance -> Total distance required for a car to safely stop -> Stopping distance = Thinking distance + Braking distance
• Thinking distance -> Distance travelled by the car while the driver is reacting
• Braking distance -> Distance travelled by the car while the braking force acts

Question 22

What factors affect thinking distance?

Answer 22

• Drugs, Tiredness, Alcohol
• Speed
• Distractions

Question 23

What factors affect braking distance?

Answer 23

• Speed
• Car conditions / brakes
• Road conditions