Question

an object of mass 0.2 kg is kept at rest. a force of 3 Newton acts on it for 5 seconds. find the distance moved by a particle in 5 seconds

1. 150m
2. 187.5m
3. 100m
4. 180m

Answer 1

Mass=0.2kg

F=3N

t=5s

u=0

Using

F=ma

3=0.2a

a=30/2

a=15m/s

s=ut+1/2at^2

s=0*5+1/2*15*5*5

s=0+1/2*375

s=187.5

Hence option 2 is correct.

Answer 2

First, write down all the physical quantities:

m = 0.2 kg

u = 0

t = 5 secs

F = 3N

We know that, F=ma (Newton's 2nd Law of Motion)

→ 3 = 0.2 × a

  $\frac{3}{0.2}$ = a

which is the same as

  $\frac{30}{2}$ = a

  15 m/s² = a

Here we have to find the distance (s)

From position-time relation equation we get,

s = ut + 1/2 at²

s = 0 + 1/2 × 15 × (5)²

  = $\frac{15}{2}$ × 25

  = 7.5 × 25

  = 187.5 m

∴ THE ANSWER IS 187.5 m

HOPE THIS HELPS ^_^