If Luis pulls straight down on the end of a wrench that is tilted θ = 30∘ above the horizontal and is r = 37 cm long, what force must he apply to exert a torque of -21 N⋅m ?

What is the major limitation to the light microscope?

What is friction? how does it affect the motion of an object?

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?