Question

cyclist decreases her velocity from 6m/s to 4m/s in 5s. Calculate

the acceleration of the bicycle.​

Answer 1

Answer :

• Acceleration = – 0.4 m/s²

Given Information :

• Initial velocity (u) = 6 m/s

• Final velocity (v) = 4 m/s

• Time taken (t) = 5 s

To calculate :

• Acceleration (a)

Calculation :

Here, we can find the acceleration by using two ways :

• By using first equation of motion
• By using acceleration formula

$\maltese$ By using first equation of motion :-

$\longmapsto \boxed { \rm { v = u + at }}$

• v denotes final velocity
• u denotes initial velocity
• a denotes acceleration
• t denotes time

$\longmapsto \rm { 4 = 6 + 5a}$

$\longmapsto \rm { 4 -6 = 5a}$

$\longmapsto \rm { -2 = 5a}$

$\longmapsto \rm { \dfrac{-2}{5} = a}$

$\longmapsto \rm \red{ -0.4 \: m/s^2 = a}$

Therefore, acceleration of the bicycle is – 0.4 m/s².

$\maltese$ By using acceleration formula :-

We know that,

• Acceleration is defined as rate of change in velocity with time. So,

$\longmapsto \rm { Acceleration = \dfrac{Change \: in \: velocity}{Time} }$

$\longmapsto \rm { Acceleration = \dfrac{Final \: velocity - Initial \: velocity}{Time} }$

$\longmapsto \rm { a = \dfrac{v - u}{t} }$

$\longmapsto \rm { a = \dfrac{4-6}{5} }$

$\longmapsto \rm { a = \dfrac{-2}{5} }$

$\longmapsto \rm \red{a= -0.4 \: m/s^2}$

Therefore, acceleration of the bicycle is – 0.4 m/s².

More Information :

Some more formulae :

First equation of motion :

• v = u + at

Second equation of motion :

• s = ut + ½at²

Third equation of motion :

• v² = u² + 2as

Where,

• v denotes final velocity

• u denotes initial velocity

• a denotes acceleration

• s denotes distance

• t denotes time