A body moves in a straight line with uniform acceleration.

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

Problem

A body moves in a straight line with uniform acceleration. (a) Starting from the definition of acceleration, derive an expression showing that the average velocity during the time interval

t

\dfrac{u+v}{2}

, where

u

and

v

are the initial and final velocities respectively. (b) Using the result of part (a), obtain the relation

s = ut + \dfrac{1}{2}at^{2}

for the displacement

s

in time

t

. (c) A car starts from rest and attains a speed of

25\,\text{m/s}

5\,\text{s}

with uniform acceleration. Using the expression derived in part (b), calculate the distance travelled in this time.

Related theory

Kinematic Equations for Uniform Acceleration
Kinematic Equations
Kinematic equations for uniformly accelerated motion
Motion in a Straight Line

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