Question

A 70 kg ice skater initially skating at a velocity of 3 m/s speeds up to a velocity of 5 m/s. How does the momentum of the skater change?

Answer 1

Answer:

140 kg m/s

Explanation:

$\underline{\bigstar\:\textsf{Given:}}$

• Mass (m) = 70 kg
• Initial velocity (u) = 3 m/s
• Final velocity (v) = 5 m/s

$\underline{\bigstar\:\textsf{To\:find:}}$

• Change in momentum of skater ($\sf{\Delta\:P}$) = ?

$\underline{\bigstar\:\textsf{Solution:}}$

Change in momentum $\sf{(\Delta\:P)\:=\:P_{final}\:-\:P_{initial}}$

Change in momentum = mv - mu ⇒ m(v - u)

[Put all the given values]

$\Longrightarrow$ m(v - u) = 70 × (5 - 3)

$\Longrightarrow$ 70 × 2

$\Longrightarrow$ 140 kgm/s

$\sf{\underline{\underline{Hence,\:change\:in\:momentum\:=\:140\:kgm/s}}}$