Isovolumetric contraction occurs during the of the electrocardiogram. P wave P-Q segment R wave S-T segment

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up

Consider two less-than-desirable options. in the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. in the second option you are driving 30 mph and crash head-on into a stationary brick wall. in neither case does your car bounce off the thing it hits, and the collision time is the same in both cases. which of these two situations would result in the greatest impact force?

What is the frequency if a wave that pases a given pount 22 times in 2 seconds