Which of the following statements is true? a. all natural radiation is at a level low enough to be safe. b. most of the nuclear radiation you are exposed to in the environment is man-made. c. you are exposed to nuclear radiation every day. d. naturally occurring nuclear radiation is called background decay.

Blood pressure the total amount of blood the heart pumps in one minute 2. cardiac output the number of times your heart beats in a minute 3. dilate the amount of blood that the heart can pump in a single beat 4. heart rate the force exerted on the walls of the blood vessels by the blood that moves through them 5. stroke volume to widen or get larger in size

Agirl throws a ball. if the ball's acceleration is 12 m/sec/sec and its mass is 0.5 kg, how much force did the girl apply to the ball?

You are driving to the grocery store at 20 m/s. you are 110m from an intersection when the traffic light turns red. assume that your reaction time is 0.50s and that your car brakes with constant acceleration. how far are you from the intersection when you begin to apply the brakes? what acceleration will bring you to rest right at the intersection? how long does it take you to stop after the light changes? the known values: vi=20m/s xi=110m t=.50s vf=0m/s xf=0m a=?