The driver of a 1000 kg car is speeding. He loses control and collides with a wall, coming to a stop. The crumple zone of the car absorbed 90 kN of force in 0.5 seconds. What was the car's speed at the time of impact?

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?