Edexcel IGCSE Physics 1 Forces & motion Question Bank

Marking points:
- use of acceleration $=\frac{\text{change in velocity}}{\text{time}}$
- substitution
- evaluation

Example:
$$\text{acceleration}=\frac{-30}{6.2}$$$$\text{acceleration}=-4.8\ \mathrm{m\,s^{-2}}$$

Accept:
- clear indication that acceleration is gradient
- -4.8 to $-5.0\ \mathrm{m\,s^{-2}}$

Ignore:
- minus sign

- clear indication that distance is area under the line
- understanding that braking distance is area of triangle section only
- evaluation

Example:
- distance = area
- distance = 0.5 x 30 x 6.2
- distance = 93 m

Accept:
- alternative method using ECF from 4(a)(i) and v^2 = u^2 + 2as, giving 93.75 m
- 54 m scores 1 mark
- 147 m scores 2 marks

Thinking distance:
- increases
- due to increased reaction time

Braking distance:
- no effect on braking distance
- due to no effect on braking time / braking force

Accept:
- idea that braking distance does not depend on human factors

A

- substitution into momentum = mass x velocity
- evaluation

Example:
- p = 0.0041 x 0.15
- p = 0.00062 kg m/s

Accept:
- standard symbols, e.g. p = m x v
- decimal or standard form
- 0.000615

Marking guidance:
- Deduct 1 mark for a power-of-ten error.

- velocity of ball increases
- momentum increases

Accept:
- ball speeds up

- substitution into F = (mv - mu) / t
- rearrangement
- evaluation

Example:
- 1.3 = 0.0041 x v / 0.0025
- v = 1.3 x 0.0025 / 0.0041
- v = 0.79 m/s

Accept:
- 0.79268...

Marking guidance:
- Deduct 1 mark for a power-of-ten error.

D

idea of carpet increases impact time;

carpet reduces rate of change of momentum (for the same speed or momentum of egg);

(carpet) reduces force;

ignore references to hard/soft floors ignore references to absorbing force or reduction in 'impact' ignore references to energy

allow RA

allow RA allow reference to given equation or word equation allow reduces deceleration or acceleration

allow RA