Question

a body of mass 500g initially at rest is acted upon by a force which causes it to move a distance of 4m in 2s, calculate the force applied​

Answer 1

Answer:

1 N

Explanation:

Given :

Mass of body is 500 g .

In term of kg is 0.5 kg.

Initially at rest mean  u = 0

Distance is 4 m

Time = 2 sec .

We know :

F = m a

also know a = v - u / t

substituting this value

F = m ( v - u / t )  [ u = 0 ]

F = m v / t

Putting given values we get :

F = 0.5 × 4 / 2 N

F = 0.5 × 2 N

F = 1 N

Thus we get applied force is 1 N.

Answer 2

Given :

Initial velocity (u) = 0 m/s

(As box is at rest)

Mass of box (m) = 500 g

Distance (s) = 4 m

Time (t) = 2 sec

Find :

Force (F) applied.

Solution :

We know that

s = ut + 1/2 at²

We have

• s = 4 m
• u = 0 m/s
• t = 2 sec
• a = ?

Substitute the known values in above formula

=> 4 = 0(2) + 1/2 a(2)²

=> 4 = 1/2 × 4a

=> 4 = 2a

=> a = 2

Acceleration (a) = 2 m/s².

Now,

From Newton's Second law of motion

F = ma

We have

• m = 500 g = 0.5 kg
• a = 2 m/s²

Substitute the known values in above formula

=> F = 0.5 × 2

=> F = 1 N

∴ Force = 1 N.