Topic 2 Motion

Question 1

In which occasions are the forces balanced ?

Answer 1

When at object is at rest and moving at constant speed the resultant force is ONewtons

Question 2

What is the formula for velocity?

Answer 2

Velocity= distance : time

Question 3

What is the difference between speed and velocity?

Answer 3

Speed is a scalar quantity and it only has the magnitude.
Velocity is a vector quantity, having both magnitude and direction

Question 4

How do we find velocity from a distance time graph?

Answer 4

Either using the formula or the gradient

Question 5

What happens if an object is at rest and an unbalanced force acts on it?

Answer 5

The object will start moving

Question 6

Describe how acceleration happens.

Answer 6

When an object is moving at constant speed and an unbalanced force acts in the direction of motion, the object will accelerate

Question 7

Describe how deceleration happens.

Answer 7

When an object is moving at constant speed and an unbalanced force acts against the direction of motion the object will decelerate.

Question 8

How can we find the distance from a velocity time graph?

Answer 8

By calculating the area under it

Question 9

How can we find the acceleration from a velocity time graph?

Answer 9

By calculating the gradient of the graph

Question 10

What is the formula for acceleration involving the initial and final velocity?

Answer 10

Acceleration= (final velocity- initial velocity) : time

Question 11

How do we find the average speed?

Answer 11

Average speed= total distance: total time

Question 12

What is the stopping distance made of?

Answer 12

Stopping distance= thinking distance + braking distance

Question 13

What are some things that can affect the thinking time?

Answer 13

Under the influence of drugs, tired,distracted, drunk

Question 14

What is the braking distance?

Answer 14

The braking distance is from the time the driver starts pressing the brake until the car stops, that’s the braking distance

Question 15

Another word for at rest

Answer 15

Stationery

Question 16

What did Galileo discover about free fall?

Answer 16

That the acceleration of a free falling object is always the same in every object, provided that there are no forced acting on it ( ex air resistance)

Question 17

What is Newton’s first law of motion?

Answer 17

That if an object is at rest and no unbalanced forces act on it the object will stay at rest.Same for an object moving at constant speed, if no unbalanced forces act on it the object will keep on moving at constant speed. Also known as inertia

Question 18

What is inertia?

Answer 18

Inertia is the laziness of an object to change its state of motion. For instance when the car is at rest and the driver accelerates the person moves backwards. If the car is moving at constant speed and the driver presses the brake then the person moves forward

Question 19

What is Newton’s second law of motion?

Answer 19

If an unbalanced force acts on an object it will accelerate in the direction of the unbalanced force.

Question 20

What is the formula for Newton’s second law of motion?

Answer 20

The unbalanced force= mass x acceleration

The unbalanced force is directly proportional to the acceleration, provided that there the mass is constant.

Question 21

What is Newton’s third law of motion?

Answer 21

For every action there is an equal and opposite reaction

Question 22

What is the formula for momentum?

Answer 22

p=m x v
Momentum= mass x velocity
Kgm/s

Question 23

Momentum is a scalar or vector quantity?

Answer 23

Vector therefore we also state the direction

Question 24

WHat is the law of conservation of momentum?

Answer 24

When two or more objects act on each other their total momentum remains. Instant provided that there are no external forces acting.
Momentum before collision= momentum after collision
If no external forces acting

Question 25

What is an Inelastic collision?

Answer 25

When two or more objects are moving separately(two bodies), collide and move of together (as one body). [ Before the collision one object can be at rest]

Question 27

What are examples of Inelastic collisions?

Answer 27

A boy running towards a skateboard,jumps on it and move off together

Question 28

After an Inelastic collision in which direction do objects move?

Answer 28

In the direction of the object with the bigger momentum

Question 29

What is an elastic collision?

Answer 29

When two objects initially move separately(two bodies), collide and move off separately (two bodies)

Question 30

What are examples of elastic collisions?

Answer 30

Two billiard balls hit each other and thrn move off separately

Question 31

What’s an explosion?

Answer 31

When one object separates to become two objects. Examples are a bullet and a gun moving at separate directions rione,a girl jumping off a boat,a balloon being deflated

Question 32

What is the principle of conservation of collision?

Answer 32

Momentum before explosion= momentum after explosion If no external forces acting

Question 33

What is an impulse?

Answer 33

A change in momentum