Question

. Describe the motion of a body which is accelerating at a constant rate of 10 m/sec2. If the body starts from rest, how much distance will it cover in 2s?

Answer 1

Given : -

A body posses an acceleration 10 m/s² . If the body starts from rest .

Required to find : -

• Distance travelled in 2 seconds ?

Equations used : -

v = u + at

v² - u² = 2as

Solution : -

A body posses an acceleration 10 m/s² . If the body starts from rest .

we need to find the distance travelled in 2 seconds .

So,

From the given information we can conclude that ;

Acceleration of the body ( a ) = 10 m/s²

Initial velocity of the body ( u ) = 0 m/s

Time taken ( t ) = 2 seconds

Now,

Let's find the final velocity of the body .

So,

Using the equation of motion ,

i.e. v = u + at

=> v = 0 m/s + 10 m/s² x 2 m/s

=> v = 0 m/s + 20 m/s²/s

=> v = 0 m/s + 20 m/s.

=> v = 20 m/s

Hence,

• Final velocity of the body ( v ) = 20 m/s

Now,

Let's find the displacement of the body ;

Using the equation of motion ,

i.e. v² - u² = 2as

=> ( 20 )² - ( 0 )² = 2 x 10 x s

=> 400 - 0 = 20 x s

=> 400 = 20s

=> 20s = 400

=> s = 400/20

=> s = 20 meters

Hence,

• Displacement of the body ( s ) = 20 meters

Since,

we know that ;

Displacement can be taken in the terms of distance in some cases . So,

• Distance travelled = 20 meters

Therefore,

Distance travelled by the body = 20 meters

Additional Information : -

What is a scalar quantity ?

Answer :

A scalar quantity is a quantity which requires only magnitude but not any direction .

Examples of some scalar quantities are ;

Distance , weight , speed etc .

what is a vector quantity ?

Answer :

A vector quantity is a quantity which requires both magnitude and direction .

Examples of some vector quantities are ;

Displacement , velocity , acceleration etc.

Answer 2

Answer:

The distance travelled by body is 20 m and final velocity is 20m/s

Explanation:

As the body is moving from rest the initially velocity is 0 and acceleration is 10 m/s² and time taken by the body is 2s. So the distance travelled be s Then ,

Initial velocity = 0

Distance Travelled = s

Time taken by the body to distance s = 2s

Acceleration of the body = 10m/s²

Use the third equation of motion : s=ut+1/2at² here s is distance , u is initial velocity , t is time , a is acceleration

$s = ut + \binom{1}{2} at^{2} \\ s = 0 \times 2 + \binom{1}{2} 10 \times {2}^{2} \\ s = 0 + 5 \times 4 \\ s = 20m$

And for final velocity the use the second equation of motion v²-u²=2as

v²-0²=2×10×20

v²=400

v=√400

v=20 m/s