Yr 10 Physics

Question 1

What is a scalar? And examples

Answer 1

Speed - just a number e.g 50mph or 20m

Question 2

What is a vector? Example

Answer 2

Number and direction e.g velocity = 50mph East

Question 3

What is displacement?

Answer 3

Distance from start to end points

Question 4

Are force, weight, acceleration, displacement ( vector or scalar ) why?

Answer 4

Vector, they can go in a direction e.g force pushing forwards

Question 5

Are mass, speed, distance, energy vector or scalars

Answer 5

Scalars, they don’t have a direction e.g speed is just a number

Question 6

Why is weight different to mass

Answer 6

Weight is mass x gravity ( 10 )

Mass = 40kg x 10 = 400N

Question 7

What is the equation to work out weight from mass

Answer 7

Weight = Mass x Gravity

W= M x G

Question 8

Give a list of forces

Answer 8

Push, pull, thrust, friction, upthrust, weight, air resistance, drag, water resistance, lift

Question 9

what are the forces acting on a car at constant velocity ( sizes )

Answer 9

Air resistance, and friction pushing backwards
Thrust bigger than air resistance and friction
Normal/ contact force and weight same size

Question 10

What are the forces acting on a car accelerating ( sizes )

Answer 10

Air resistance, and friction pushing backwards
Thrust much bigger than air resistance and friction
Normal/ contact force and weight same size

Question 11

What are the forces acting on a car decelerating ( sizes )

Answer 11

Air resistance, and friction pushing backwards
Thrust smaller than air resistance and friction
Normal/ contact force and weight same size

Question 12

What are the forces acting on a car that is stationary ( sizes )

Answer 12

Just normal/ contact force and weight same size

Question 13

Forces on an accelerating boat

Answer 13

Thrust bigger, water resistance smaller
Air resistance medium but smaller than thrust
Weight and upthrust same size ( so the boat doesn’t sink or fly )

Question 14

What is a resultant force

Answer 14

The sum effect of more than one force is called the resultant force

Question 15

What is the resultant force on a box

Moving 50N left and 30N right

Answer 15

50 - 30 = 20N left

Question 16

How do you calculate the moment

Answer 16

Force x distance

Force = 8
Distance = 0.2 metres 
Moment= 1.6

Question 17

How do you calculate moments in gears

Answer 17

Force x gear radius

Question 18

What happens if you have a smaller gear at the back

Answer 18

Low gear: multiplies effort, every one turn of pedals = a number of turns for wheel

Question 19

What happens if you have a bigger gear at the back

Answer 19

High gear: less powerful

Question 20

How do you find the centre of mass?

Answer 20

1. Put a hole in one corner of the card shape and suspend from stand rod
2. Use a plum line placed by the card to draw a vertical line down it
3. Repeat the procedure hanging the card from different corners

Question 21

Why does an object balance?

Answer 21

The larger the surface area of the base the more stable the shape is
It balances if the centre of mass is directly above the base

Question 22

What is stability

Answer 22

The measure of how likely it is for an object to topple over when pushed or moved

Question 23

What are the forces applied by two gears

Answer 23

They are equal

Question 24

What is the relation between ratio of teeth, diameter and moment

Answer 24

They are all equal

Question 25

What is the turning speed related to

Answer 25

Ratio of moment

Moment a: 5nm
Moment b: 2.5nm
Turning speed ratio: 5:2.5 = 2:1

Question 26

Describe why an object doesn’t fall down an incline plane and then why it would

Answer 26

It wouldn’t because the force of gravity ( straight down ), perpendicular weight ( contact force keeping object up )and parallel weight ( weight running parallel with the slope ) are equal.

It would then fall down if the parallel weight became greater than the force of gravity, either by angle of slope or weight of object increasing