Question

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. But she does have devices to measure distance and time accurately. She knows her own mass is 76.4 kg, but she is unsure of the mass of a large gas canister in the airless rocket. When this canister is approaching her at 3.50 m/s, she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s. What is the mass of the canister?

Answer 1

Answer:90.3 kg

Explanation:

Given

Mass of astronaut $m=76.4 kg$

Initial velocity of canister $v_1=3.5 m/s$

Final velocity of canister $v_2=1.3 m/s$

Final speed of Astronaut $v_f=2.6 m/s$

let M be the mass of canister

As there is no external force therefore we can conserve momentum

$M\cdot v_1=mv_f+M\cdor v_2$

$M(3.5-1.3)=76.4\times 2.6$

$M=\frac{76.4\times 2.6}{2.2}$

$M=90.29\approx 90.3 kg$