Physics January 2020 PPE

Question 1

What is Newtons first law?

Answer 1

If the resultant force on a stationary object is zero, the object will remain stationary. If the resultant force on a moving object is zero then the object will continue to move at the same velocity.(Same speed and direction)

Question 2

What formula describes Newtons second law?

Answer 2

F = m * a

Force (N) = Mass (kg) * Acceleration (m/s²)

Question 3

What different forms can acceleration be?

Answer 3

Starting, Stopping, Speeding up, Slowing down, Changing direction

Question 4

What is acceleration proportional to?

Answer 4

Resultant force

Question 5

What does a distance/time graph show?

Answer 5

How far something has traveled

Question 6

What does a velocity/time graph show?

Answer 6

How an object’s velocity changes over time

Question 7

What does a curve mean on a velocity/time graph and a distance/time graph?

Answer 7

Changing acceleration

Question 8

What is inertia?

Answer 8

The tendency for motion to remain unchanged

Question 9

What does inertial mass measure?

Answer 9

How difficult it is to change the velocity of an object

Question 10

What 3 factors affect inertial mass?

Answer 10

Force
Mass
Acceleration

Question 11

If 2 objects push off of each other, both with different masses, which would accelerate more?

Answer 11

The object with the smaller mass

Question 12

How do you calculate momentum?

Answer 12

P = m * v

Momentum (kg m/s) = mass (kg) * velocity (m/s)

Question 13

Is momentum a scalar quantity or a vector quantity?

Answer 13

A vector quantity. It has size and direction

Question 14

What is conservation of momentum?

Answer 14

When the total momentum before an event (eg. a collision) is the same as after the event

Question 15

How do you find speed from a distance/time graph?

Answer 15

The speed is the gradient so

change in vertical / change in horizontal

Question 16

What is the weight of a 25kg mass on Earth?

Answer 16

25 * 10 = 250N

Question 17

What is the force that keeps something moving in a circle called?

Answer 17

Centripetal force

Question 18

If an object is moving in a circle, which way does the force act towards?

Answer 18

The centre of the circle

Question 19

What is the velocity of an object moving at a constant speed in a circle?

Answer 19

The velocity is constantly changing as it is constantly changing direction

Question 20

What is the gravitational field strength of Earth?

Answer 20

10N/kg

Question 21

How do you calculate weight?

Answer 21

Weight = mass * gravitational field strength

Question 22

Why is mass different from weight?

Answer 22

Weight is the force on an object due to gravity.

Mass is a scalar quantity

Question 23

What is a scalar quantity?

Answer 23

A physical quantity that has no direction

Question 24

What is a vector quantity?

Answer 24

A physical quantity that has a direction

Question 25

Name 2 scalar quantities

Answer 25

Speed, distance, mass, energy, temperature, time

Question 26

Name 2 vector quantities

Answer 26

Force, velocity, displacement, weight, acceleration, momentum

Question 27

define acceleration

Answer 27

Acceleration is how quickly something speeds up

Question 28

How do you calculate acceleration?

Answer 28

``` A = ( v - u) / t acceleration = change in velocity / time ```

Question 29

What does uniform acceleration mean?

Answer 29

Constant acceleration

Question 30

Give on example of uniform acceleration

Answer 30

Acceleration due to gravity