Question

A force acts for 0.28sec on an object having mass 1.4kg initially at rest.The force stops to act but the object moves through 4m in next 2 sec find the magnitude of the force? Pls answer fast. ( Who ever write the correct solution for the given answer quickly will be marked as the brainliest answer.. hurry up.It is urgent) Hint- the answer is 10 N

Answer 1

✪ᴀɴsᴡᴇʀ✪

• $F = 10N$

★ᴇxᴘʟᴀɪɴᴀᴛɪᴏɴ★

In the first 0.28 sec, the object initially at rest(u = 0) accelerated due to the force applied. Let v be the velocity of the object after 0.28 sec.

From Newton's Second Law,

$F = ma = m\frac{\left(v-u\right)}{t}$

$\implies F = 1.4\times \frac{(v-0) }{0.28}$

$\implies F = 5v...(1)$

After the application of force is stopped, the object moves 4m in 2 sec(uniform motion) with velocity v.

$\implies s = vt$

$\implies 4m = v\times 2s$

$\implies v = 2m/s$

Using this in (1),we get

$\implies F = 5\times 2$

$\implies F = 10N$