If the distance of a galaxy is 2,000 Mpc, how many years back into the past are we looking when we observe this galaxy

A5 nc point charge is at the origin and a second 3 nc point charge is on the x-axis at x = 0.8 m. find the magnitude and direction of the electric field on the x-axs at x = 0.2 m. you may express the direction by letting positive field mean the positive x direction

Work = force × a. work b. energy c. distance d. momentum

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?