General Physics 1.2 Motion

Question 1

What are the 3 main components of motion?

Answer 1

1. Speed
2. Direction
3. Acceleration (change in speed)

Question 2

Give the equation for average speed

Answer 2

average speed (m/s) = distance (m) / time (s)
v=d÷t

Question 3

What is the difference between speed and velocity?

Answer 3

• Speed is scalar, so doesn’t include direction
• Velocity is a vector, so has a direction

Question 4

Give an equation for acceleration.

Answer 4

acceleration (m/s2) = final velocity - initial velocity (m/s)/ time (s)

Question 5

What is the gradient of a displacement time graph?

Answer 5

The velocity.

Question 6

What does a curved line represent on a displacement time graph?

Answer 6

Acceleration (or deceleration).

Question 7

What does the gradient of a velocity-time graph represent?

Answer 7

Acceleration at that point.

Question 8

What does the area under a velocity-time graph represent?

Answer 8

The displacement.

Question 9

What does a curved line represent on a velocity-time graph?

Answer 9

Changing acceleration.

Question 10

What does a speed-time graph look like when an obiect is at rest?

Answer 10

The y-axis (speed) = 0.

Question 11

What does a speed-time graph look like when an object moves at constant speed?

Answer 11

A flat line (zero gradient).

Question 12

What does a speed-time graph look like when an object is moving with changing speed?

Answer 12

A non-zero gradient.

Question 13

What is the value of acceleration due to gravity at the Earth’s surface?

Answer 13

9.81 m/s2

Question 14

Explain how terminal velocity is reached

Answer 14

• Initially in free fall, the only force is weight –> so acceleration at start is acceleration of gravity
• As speed increases, air resistance increases
• Eventually air resistance = weight, so there is no acceleration, resulting in terminal velocity

Question 15

What is deceleration?

Answer 15

Negative acceleration (slowing down, decreasing speed).