Question

A force of 100N acts on a body of mass 2kg for 10s. What is the change in momentum of a body? Plz answer in a simple way and explain step by stem

Answer 1

$\small{\underline{\sf{\pink{Find:\rightarrow}}}}$

$\rm{Change\ in\ momentum??}$

$\large{\underline{\sf{\red{Given:\rightarrow}}}}$

• $\sf{Force= 100N}$
• $\sf{Mass = 2kg}$
• $\sf{Time=10s}$

$\large{\underline{\sf{\orange{SoLution:\rightarrow}}}}$

$\sf{Momentum (p) = mv}$

$\sf{Where, m = mass\ and\ v = velocity\ of\ body.}$

Change in momentum =

$\boxed{\sf{\blue{mv_2 - mv_1 = m(v_2 - v_1) = m(\Delta v)}}}$

Using the formula F=ma

$\tt { 100 = 2\times a \implies a= 50 m/s^2 }$

Now we know that acceleration is the rate of change of velocity or a = ∆v/t

$\sf{\Delta v = a\times t = 50\times10 = 500 m/s}$

Change in momentum=

$\sf {\Delta p = 2\times 500 = 1000 kgm/s}$

∴Change in Momentum = 1000kgm/s

______________________________

Answer 2

To Find :

• we need to find momentum of body

Solution :

• Force = mass × Acceleration

➔ 100N = 2kg × a

➔ a = 100/2

➔ a = 50m/s²

Finding velocity of body using first equation of motion V = u + at

• initial velocity (u) = 0
• Time (t) = 10s
• Acceleration (a) = 50m/s²
• Final velocity = ?

V = 0 + 50 × 10

V = 0 + 500

V = 500m/s

Now,

Finding momentum of body

we know that,

• momentum = mass × velocity

➔ p = 2 × 500

➔ p = 1000kg m/s

Hence,

Momentum of body is 1000 kg m/s

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More information :-

Momentum :- The momentum of body is defined as the product of it's mass and velocity .

⠀⠀⠀Momentum = mass × velocity

⠀⠀⠀⠀⠀p = mv

Where

• p = momentum
• m = mass
• v = velocity

› SI unit of momentum is kilogram meters per second(kg m/s).

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