Question

(b) A car acquires a velocity of 72 km per hour in 10 seconds starting from rest. Find (i) the acceleration,
(ii) the average velocity, and (iii) the distance travelled in this time​

Answer 1

Answer:

using v= u + at , u0 since it was at rest

72*5/18 = 20m/s

20=10a a =2 m/s^2

Explanation:

Answer 2

To Find:-

(i) the acceleration ; (ii) the average velocity, and (iii) the distance travelled in this time ??

Explanation:

Given:

Initial velocity of the car (u) = 0

Final velocity of the car (v) = 72 km/h

Time taken (t) = 10 seconds

Since the time is in seconds we have to convert the distance into metre.

We know that,

1 km = 1000 m

So, by the problem

$\dfrac{72 \times 1000m}{60 \times 60s} = 20 m/s$

Now,

Acceleration of the car:

Solution :

step-by-step explanation:

( i ) Acceleration of the car (a)

$= \dfrac{v-u}{t}$

$= \dfrac{(20-0) m/s}{10 s} = 2 m/{s}^{2}$

Therefore, the acceleration of the car is 2 m/s².

( ii ) Average Velocity Of The Car:

$Average \: \: velocity = \dfrac{u+v}{2}$

$= \dfrac{0+20}{2} m/s \\ = 10 m/s$

Therefore,the average velocity of the car is 10 m/s.

( iii ) Distance travelled by the car:

Distance travelled (S)

$= ut+ \frac{1}{2} a{t}^{2}\\ 0 + \frac{1}{2} \times 2 \times {10}^{2}$

= 100 metres.

Therefore , the distance travelled by the car is 100 m.

$\green{Required \: \: Answer}$

( i ) The acceleration of the car is 2 m/s².

( ii ) The average velocity of the car is 10 m/s.

( iii ) The distance travelled in this time by the car is 100m.