Question

A force when applied on a block of 10 kg mass produces an acceleration of 5 m/s2 . When the same force is applied on a different block initially at rest, the block gains a velocity of 2 m/s in 1 sec. Calculate the magnitude of force in Newton and mass of the second block.

Answer 1

Step-by-step explanation:

acceleration, a =

m

F

=

10

25

=2.5m/s

2

Using v = u + at

we get, v - u = at (velocity gain is 10m/s, so v-u = 10)

10 = 2.5t

t = 4s

Answer 2

Given,

Same force is applied on two blocks.

Mass of first block = 10kg

Acceleration of first block = 5 m/s²

Second block starts from rest.

Second block gains a velocity of 2 m/s in 1 second.

To find,

Magnitude of force in Newton and mass of the second block.

Solution,

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

First of all, we have to calculate the magnitude of force.

We know that,

Force = Mass × Acceleration

So, from the data given about the first block :

Force = 10 × 5 = 50 kg.m/s² = 50N

(1 kg.m/s² = 1 Newton)

For second block :

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

Final velocity (v) = 2 m/s

Time (t) = 1 second

Acceleration (a) = ?

According to the kinematics,

a = (v-u)/t

a = (2-0)/1 = 2 m/s²

It is given that the force is same for two blocks.

So, Force on first block = Force on second block = 50 N

Now, calculating the mass of ths second block :

Again,

Force = Mass × Acceleration

50 = Mass × 2

Mass = 50/2 = 25kg

Hence, magnitude of force is 50N and mass of second block is 25kg