Question

A particle of mass 2kg is moving with a velocity of 4m/s attains a velocity of 8m/s in 2 second. Calculate the amount of force needed to attend this velocity.

Answer 1

Given,

Initial velocity of the particle (u) = 4m/s

Final velocity of the particle (v) = 8m/s

Mass of the body (m) = 2kg

Time taken (t) = 2s

To find,

The force needed by the body to attend the velocity

Solution,

According to Newton's 2nd law of motion, we know that:

F = m(v - u)/t

Where F is equal to the magnitude of the force

[Anything that can be pushed or pulled is called Force. Force is a vector quantity.]

By substituting values in the above equation, we get:-

=> F = $\frac{2(8-4)}{2}$

=> F = $\frac{2(4)}{2}$

=> F = $\frac{8}{2}$

=> F = 4 N

Hence, the required amount of force is 4 N.  

Note:

1. S.I. unit of force is Newton(N). Its C.G.S. unit is dyne.
2. Common symbols to denote force: F

Answer 2

$\underline{ \underline{ \purple{ \huge \sf \: answer}}}$

given information,

• mass of participle (M)= 2kg
• initial velocity (u)= 4 M/S
• final velocity (v) = 8 M/S
• time (T) = 2 second

$\large{ \red {\underline{according \: the \: newtons \: second \: laws}}}$

rate of change momentum is proportional to applied force

Thus,

F = ∆p

∆t

= F = mu - mv

t

= F = 2 × 8 - 2 × 4

2

= F = 8 - 4

$\large{ \pink{ \fbox{ \: f \: = 4n}}}$

force required to change the velocity is 4 n

hope its help u