Can an electric field exist in a vacuum?

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?

Humid air is a better electrical conductor than dry air. explain why you are most likely to receive a shock after walking across a carpet when the air is dry than when the air is humid.

An athlete performing a long jump leaves the ground at a 27.0 degree angle and lands 7.80m away. what was the takeoff speed?