Two 4.0-Ω resistors are connected in parallel, and this combination is connected in series with 3.0 Ω. What is the effective resistance of this combination?

This is the substance(s) formed in a chemical reaction.

What is the coefficient of kinetic friction μk between the block and the tabletop?

Aballoon is rising vertically upwards at a velocity of 10m/s. when it is at a height of 45m from the ground, a parachute bails out from it. after 3s he opens his parachute and decelerates ata a constant rate 5m/s.when. (a) what was the height of the parachutist above the ground when he opened his parachute? (b)how far is the parachutist from the balloon at t=3s? (c)with what velocity does the parachutist hit the ground? (d)after how long does the parachutist hit the ground after his exist from the balloon?