Question

A bus acceleration uniformly from rest and acquires a speed of 72 km ph 10 sec find the acceleration

Answer 1

Given:-

• Initial velocity ,u = 0m/s
• Final velocity ,v = 72km/h
• Time taken ,t = 10s

To Find:-

• Acceleration ,a

Solution:-

According to the Question

It is given that bus acceleration uniformly from rest and acquires a speed of 72 km/h 10 sec.

we have to calculate the acceleration of the bus .

Firstly we change the speed into m/s.

→ v = 72 × 5/18

→ v = 4×5

→ v = 20m/s

Now, we know that acceleration is defined as the rate of change in velocity.

• a = v-u/t

where,

• v is the final velocity
• a is the acceleration
• u is the initial velocity
• t is the time taken

Substitute the value we get

$\longrightarrow$ a = 20-0/10

$\longrightarrow$ a = 20/10

$\longrightarrow$ a = 2m/s²

• Hence, the acceleration of the bus is 2m/s².

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Answer 2

Answer:

Given :-

• A bus acceleration uniformly from rest and acquires a speed of 72 km/h in 10 seconds.

To Find :-

• What is the acceleration.

Formula Used :-

$\clubsuit$ First Equation Of Motion Formula :

$\mapsto \sf\boxed{\bold{\pink{v =\: u + at}}}$

where,

• v = Final Velocity
• u = Initial Velocity
• a = Acceleration
• t = Time

Solution :-

First, we have to convert final velocity (v) km/h into m/s :

$\implies \sf Final\: Velocity =\: 72\: km/h$

$\implies \sf Final\: Velocity =\: 72 \times \dfrac{5}{18}\: m/s\: \: \bigg\lgroup \sf\bold{\pink{1\: km/h =\: \dfrac{5}{18}\: m/s}}\bigg\rgroup$

$\implies \sf Final\: Velocity=\: \dfrac{360}{18}\: m/s$

$\implies \sf \bold{\purple{Final\: Velocity =\: 20\: m/s}}$

Given :

$\bigstar\: \: \rm{\bold{Initial\: Velocity (u) =\: 0\: m/s}}$

$\bigstar\: \: \rm{\bold{Final\: Velocity (v) =\: 20\: m/s}}$

$\bigstar\: \: \rm{\bold{Time (t) =\: 10\: seconds}}$

According to the question by using the formula we get ,

$\longrightarrow \sf 20 =\: 0 + a(10)$

$\longrightarrow \sf 20 =\: 0 + 10a$

$\longrightarrow \sf 20 - 0 =\: 10a$

$\longrightarrow \sf 20 =\: 10a$

$\longrightarrow \sf \dfrac{2\cancel{0}}{1\cancel{0}} =\: a$

$\longrightarrow \sf \dfrac{2}{1} =\: a$

$\longrightarrow \sf 2 =\: a$

$\longrightarrow \sf\bold{\red{a =\: 2\: m/s^2}}$

$\therefore$ The acceleration of the bus is 2 m/s².