Question

An 80 kg astronaut was stuck in the middle of space with only an apple. He threw the 2kg apple to the right at 20m/s. If the astronaut was 10m to the right of his spaceship, how long did it take him to reach the ship after throwing the apple?

Answer 1

t = 20 s

Step-by-step explanation:

given,

mass of astronaut = 80 kg

mass of apple = 2 Kg

speed of the apple = 20 m/s

distance between the spaceship = 10 m

time= ?

initial velocity of astronaut = 0 m/s

using conservation of momentum

M V = m₁ v₁ + m₂ v₂

0 = 80 v₁ + 2 x 20

80 v₁ = -40

v₁ = - 0.5 m/s

- ve sign because motion is in opposite direction

distance = speed x time

`t = (10)/(0.5)`

t = 20 s

time taken to reach the ship is equal to 20 s