Question

A body of mass 100g moving with a velocity of 10.0m/s collides with a wall .if after the collision it moves with a velocity of 2.0m/s in the opposite direction,calculate the change in momentum

Answer 1

-1.2 kg - m/s

Step-by-step explanation:

`\pink{\frak{Given}}\begin{cases}\textsf{ A body of mass 100g moving with a velocity of 10.0m/s collides with a wall .}\\\textsf{ After the collision it moves with a velocity of 2.0m/s in the opposite direction.}\end{cases}`

And we need to find out the change in momentum of the body . Here ,

• velocity before collision (u) = 10m/s
• velocity after collision (v) = 2m/s .

We know that momentum is defined as amount of motion contained in a body . Mathematically ,

`\sf\longrightarrow momentum (p)= mass(m) * velocity(v)`

Therefore change in momentum will be,

`\sf\longrightarrow \triangle p = mv - mu`

Since the direction of velocity changes after the collision , the velocity will be -2m/s .

`\sf\longrightarrow \Delta p = 100g( -2m/s -10m/s) \\`

`\sf\longrightarrow \Delta p =(100)/(1000)kg ( -12m/s) \\`

`\sf\longrightarrow \Delta p = 0.1 kg * -12m/s \\`

`\sf\longrightarrow \boxed{\bf \Delta p = -1.2 \ kg-m/s} \\`