A car travels along a straight road towards the north

PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

A car travels along a straight road towards the north. Take the positive direction to be towards the north. The car has an initial velocity of

25\,\text{m/s}

and comes to rest in

10\,\text{s}

with uniform acceleration. (i) Write the algebraic signs (positive or negative) of the initial velocity

u

, final velocity

v

and acceleration

a

for this motion. (ii) Calculate the value of the acceleration

a

. (iii) Determine the displacement of the car before it comes to rest, clearly showing how the sign of

a

is handled in the calculation. (iv) Is the car said to be under positive acceleration or negative acceleration? Justify your answer briefly.