Past Papers

Question 1

Find acceleration from velocity

Answer 1

Differentiate

Question 2

Find distance/s from velocity

Answer 2

Integrate

Question 3

Why is a spinning object accelerating despite moving at a constant speed

Answer 3

Changing direction

Question 4

Direction of acceleration of spinning object

Answer 4

Towards the centre

Question 5

How to calc dθ from revolution per second

Answer 5

x2π

Question 6

Angular velocity unit

Answer 6

ω

Question 7

Calc magnitude of centripetal force

Answer 7

F = mrω² = mv²/r

Question 8

If a question says horizontal component and involves tension… what do you do?

Answer 8

Use W=mg to find vertical component, then Pythagoras to get to answer.

Question 9

Something is spinning vertically, explain forces at highest and lowest point

Answer 9

Highest- Weight and tension both pulling object down

Lowest- Weight and tension pull in opposing directions

Question 10

Determine magnitude of tension when sphere is at its highest and lowest point (moving in vertical circle)

Answer 10

T=F-W

T=F+W

Question 11

Radial acceleration

Answer 11

aᵣ a.k.a. Centripetal acceleration

Question 12

Speed of spinning object decreases

Answer 12

Angle decreases due to horizontal component of tension decreasing and weight remaining constant

Question 13

What is a black body

Answer 13

They absorb all the radiation that hits them and emit a full distribution of wavelengths

Question 14

Apparent brightness

Answer 14

(b) How bright a star APPEARS to be to an observer on Earth

Question 15

Power per Unit Area

Answer 15

(P/A) The power output of the surface of a star per meter squared

Question 16

Luminosity

Answer 16

(L) The total power output of a star

Question 17

Two meanings of T

Answer 17

Temperature and period

Question 18

Two meanings of L

Answer 18

Luminosity and Angular momentum

Question 19

Moment of inertia

Answer 19

I=xmr²

Hoops and rings behave like point mass
Solid cylinder behave like disc about centre

Question 20

Calculate angular acceleration from torque

Answer 20

τ=Ia

Question 21

Conservation of angular momentum

Answer 21

I ₁ω ₁=I ₂ω ₂=mvr=mr ²ω

Question 22

Find Moment of Inertia with Energy and angular velocity?

Answer 22

E ₖ=1/2Iω ²

Question 23

Gravitational Field strength

Answer 23

F₉=W

Question 24

Tangential velocity

Answer 24

v

Question 25

Orbital period

Answer 25

v꜀=2πr/T

Question 26

What is meant by the grav potential of a point in space

Answer 26

Work done in moving unit mass from infinity (to that point)

Question 27

Gravitational Potential

Answer 27

V

Question 28

F=GMm/r²=?

Answer 28

mv²/r=mrω²=mr(2π/T)²

Question 29

Explain what is meant by a gravitational potential of x

Answer 29

X joules of energy transferred in moving unit mass from infinity to that point

Question 30

Determine potential energy of x as a result of change in orbit

Answer 30

V(low)-V(high)

Multiply by no of kg