Rate my dog 1 to 100 its a shih tzu

An object moves from the position +34m to the position -15m in 15 seconds. what is it's total displacement? what is it's average velocity?

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?

The force it would take to accelerate an 900-kg car at the rate of 6m/s2