Question

Two balls each of mass 250 g moving in opposite directions each with a speed 16 m/s collide and rebound with the same speeds. The impulse imparted to one ball due to the other is

• A. 4 kg m s^-1
• B. 16 kg m s^-1
• C. 8 kg m s^-1
• D. 2 kg m s^-1

Hint:

Impulse is the change in momentum: \( Impulse} = m(v - u) \). Be careful with direction — if velocity reverses, the sign changes.

Answer 1

The Correct Option is C

Step 1: Given data
Mass of each ball \(m = 250 \, \text{g} = 0.25 \, \text{kg}\)
Initial velocity \(u = 16 \, \text{m/s}\), final velocity \(v = -16 \, \text{m/s}\) (since it rebounds with the same speed in the opposite direction)
Step 2: Calculate impulse
Impulse is given by:
\[ \text{Impulse} = \Delta p = m(v - u) = 0.25 \times (-16 - 16) = 0.25 \times (-32) = -8 \, \text{kg m/s} \]
Step 3: Take magnitude
Impulse magnitude = \(|-8| = 8 \, \text{kg m/s}\)
Step 4: Choose the correct option
So, the correct answer is \(\boxed{8 \, \text{kg m/s}}\), which is option (3).