Three particles a, b and c are thrown from the top of a tower with the same speed. a is thrown straight up, b is thrown straight down and c is thrown horizontally. they hit the ground with a. equal speed at same time b. equal speed one after another c. unequal speeds one after another d. unequal speed at same time

How many dots must be added to the symbol to properly represent a standard nitrogen ion? a) 1 b) 3 c) 5 d) 8

20. threshold braking in the vehicle's braking system occurs when a. the brake pedal is pushed, heel on floorboard, with full foot pressure. b. the brakes are exerting full braking power, without traction loss. c. the driver begins pushing down the brake pedal, with moderate slowdown. d. the brakes just begin to take hold with a gradual slowdown.

Apulley with mass mp and a radius rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot.