2 (a) (i) Which of these is the correct equation that relates force, mass and acceleration? A F = m + a B F = m - a C F = m × a D F = m + a (ii) A cyclist has a mass of 70kg - Edexcel - GCSE Physics Combined Science - Question 2 - 2020 - Paper 1

To find the force, we can use the formula:
$F = m × a$
Given that the mass $m = 70$ kg and acceleration $a = 2.0$ m/s², we have:
$F = 70 ext{ kg} × 2.0 ext{ m/s²} = 140 ext{ N}$
Thus, the force needed is 140 N (Newtons).

To calculate the average speed, we use the formula:
$\text{average speed} = \frac{\text{distance}}{\text{time}}$
Here, the distance is 1200 m and the time is 80 s. Therefore,
$\text{average speed} = \frac{1200 ext{ m}}{80 ext{ s}} = 15 ext{ m/s}$
The average speed of the cyclist is 15 m/s.