Question

In order to gain a speed of 12m/s , how long should a force of 30N be exerted on a body of mass 5 kg?​

Answer 1

Answer:

We know that

F= ma

Force= Mass×Acceleration

But we don't know the ime

Also a= v-u/t

So,

$f = m \times \frac{v - u}{t}$

Here the change in velocity= 12

Taking u as 0

f=m×v-u/t

But yet we don't know time

f=m×v-u/t

ft=m×v-u

t=m×v-u/f

Here

m= 5

v=12

u=0

f=30

that is

t=(5×12-0)/30

t=60/30

t=2

therefore the time is 2 seconds

Answer 2

Explanation:

We know that

F= ma

Force= Mass×Acceleration

But we don't know the ime

Also a= v-u/t

So,

f = m \times \frac{v - u}{t}f=m×

t

v−u

Here the change in velocity= 12

Taking u as 0

f=m×v-u/t

But yet we don't know time

f=m×v-u/t

ft=m×v-u

t=m×v-u/f

Here

m= 5

v=12

u=0

f=30

that is

t=(5×12-0)/30

t=60/30

t=2

therefore the time is 2 seconds