Question

A body initially at rest travels a distance of 100 m in 5s with a constant acceleration.calculate acceleration and final velocity at the end of 5s

Answer 1

Answer:

acceleration = 8 m/s^2

velocity = 40 m/s

Answer 2

Given :-

A body which is initially at rest travels a distance of 100 meters in 5 seconds with a constant acceleration .

Required to find :-

• Acceleration ?

• Final velocity at the end of 5 seconds ?

Equations used :-

S = ut + ½ at²

v² - u² = 2as

Solution :-

A body which is initially at rest travels a distance of 100 meters in 5 seconds with a constant acceleration .

We need to find the ;

Acceleration ?

Final velocity at the end of 5 seconds ?

So,

From the given information we can conclude that ;

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

• Distance travelled ( s ) = 100 meters

• Time taken ( t ) = 5 seconds

Now,

Let's find the acceleration of the body .

So,

Using the equation of motion ;

i.e. s = ut + ½ at²

100 = 0 x 5 + ½ x a x 5 x 5

100 = 0 + ½ x a x 25

100 = ½ x a x 25

100 = a x 12.5

100 = 12.5a

12.5a = 100

a = 100/12.5

a = 1000/125

a = 8 m/s²

Hence,

• Acceleration of the body ( a ) = 8 m/s²

Now,

Let's find the final velocity at the end of 5 seconds ;

Using the equation of motion ,

i.e. v² - u² = 2as

v² - ( 0 )² = 2 x 8 x 100

v² - 0 = 2 x 8 x 100

v² = 2 x 8 x 100

v² = 1600

v = √1600

v = 40 m/s

Hence,

• Final velocity of the body ( v ) = 40 m/s

Therefore,

Acceleration of the body = 8 m/s²

Final velocity of the body at the end of 5 seconds = 40 m/s

Additional Information :-

These equations of motion are only applicable when the acceleration is constant

The S.I. unit of acceleration is m/s² .

The laws of the motion are ;

( i )

A body continues to be in the state of rest of motion until or unless some external force is applied on it .

( ii )

The rate of change of momentum is directly proportional to the unbalanced force in the direction of force .

( iii )

For every action there is an equal opposite reaction