Question

1. A certain force exerted for 1.2 second
to raises the speed of an object from 1.8mke
fogar aom/pihats the same force is applied
for aqsec by how much does the aspeed
changes in 2 sec.

Ans-- 4 m/s​

Answer 1

Answer:

Explanation:

Given A certain force exerted for 1.2 second   raises the speed of an object from 1.8 m to 4.2 m/s the same force is applied  for 2 sec by how much does the speed  changes in 2 sec.

We know that a = v – u / t and f = ma

So f = m (v – u) / t

      = m (4.2 – 1.8) / 1.2

      = m (2.4) / 1.2

So f = 2 m

Now force is applied for 2 s

So f = m (v – 4.2) / 2

So 2m = m (v – 4.2) / 2

Now v – 4.2 = 4

So v = 4 + 4.2

Or v = 8.2 m / s

Therefore the change in velocity will be 8.2 – 4.2 = 4 m / s