* Initial height (h) = 20 m
* Initial velocity (u) = 0 m/s (dropped with zero initial momentum)
* Final momentum (p) = 40 kg·m/s
* Acceleration due to gravity (g) = 10 m/s²
* Mass (m) = ?
Step 1: Find the final velocity when the body hits the ground
Using the equation of motion: v² = u² + 2gh
Where:
* v = final velocity
* u = initial velocity = 0 m/s
* g = 10 m/s²
* h = 20 m
v² = 0² + 2 × 10 × 20
v² = 400
v = 20 m/s
Step 2: Calculate the mass using momentum
We know that momentum (p) = mass (m) × velocity (v)
Given: p = 40 kg·m/s and v = 20 m/s
Therefore:
40 = m × 20
m = 40/20
m = 2 kg
Answer: The mass of the body is 2 kg (Option A)
