The race officials want to set up portable bleachers near the finish line. each set of bleachers is 4.50 meters long and 2.85 meters wide. how many square meters of open ground space do they need for each set?

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.

All the simple machines make work easier to do by changing the or of a force. a. size; type b. work; type c. size; direction d. type; direction

The image shows the positions of a car on a roller coaster track. arrange the cars in order based on their gravitational potential energy. begin with the lowest potential energy and end with the highest.