On average, a human hair grows about .5 inches per month. If someone had 12 inches of hair and were to dye a different color, then they will have to let their hair grow a foot before it will be back to it’s normal length and color. How long will that take

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 77.4 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?