Question

Find the time taken by a body of mass 16 kg to come to rest from a uniform velocity of magnitude 10 m/s, when a force of 4N is applied continuously
(a) 20 s
(b) 30 s
(c) 40 s
(d) 50 s​

Answer 1

Answer:

C 40 s

Explanation:

v=0

u= 10m/s

F=4N

mass= 16 kg

F=ma

4=16*a

a = 4/16=0.25 m/s^2

v=u+at

0=10+0.25t

0.25t=10

t= 10/0.25=1000/25=40sec

Answer 2

Given,

Mass of the body = 16 kg

Starts from rest.

Comes to uniform velocity of 10 m/s

Amount of force = 4N

To find,

Time taken by the body to reach the given uniform velocity.

Solution,

We can simply solve this numerical problem by using the following process.

Now, we have to calculate the amount of acceleration.

We know that -

Force = Mass × Acceleration

4 = 16 × Acceleration

16 × Acceleration = 4

Acceleration = 4/16 = ¼ m/s²

Here,

Initial velocity (u) = 0 m/s (as starts from rest)

Final velocity (v) = 10 m/s

Acceleration (a) = ¼ m/s²

Time (t) = ?

Now, according to kinematics,

v = u + at

10 = 0 + (¼×t)

10 = t/4

t = 10×4 = 40 seconds

Hence, the body will take 40 seconds (option c)