June 2023 Paper 3 Mechanics Q1

EdexcelCurrent spec3 marksSUVAT

1. A car is initially at rest on a straight horizontal road.

The car then accelerates along the road with a constant acceleration of \(3.2\ \text{m s}^{-2}\)

Find

(a) the speed of the car after 5 s, (1)

(b) the distance travelled by the car in the first 5 s. (2)

Scheme	Marks	AO
16 \((\text{m s}^{-1})\) seen as the answer	B1	1.1b
	(1)

Mark scheme (b)

Scheme	Marks	AO
\(s = \dfrac{1}{2} \times 3.2 \times 5^2\) OR \(s = \dfrac{(0+16)}{2} \times 5\) OR \(s = (16 \times 5) - \dfrac{1}{2} \times 3.2 \times 5^2\) OR \(16^2 = 2 \times 3.2 \times s\) OR from a v-t graph, \(s = \dfrac{1}{2} \times 5 \times 16\)	M1	3.1b
\(s = 40\) (m)	A1	1.1b
	(2)
	(3 marks)

Notes

M1: Complete method to find an equation in \(s\) only, possibly using their ‘16’
Allow ‘reversed motion’: use of \(s = vt - \dfrac{1}{2}at^2\) with \(v = 0\)
i.e. \(s = -\dfrac{1}{2} \times 3.2 \times 5^2\) can score M1
and \(s = -40\) so distance is 40 (m) can score the A1

A1: cao. Must be positive.

N.B. correct answer only, in (b), can score both marks.