About how much power does a sprinter produce if he transforms 2.7 kJ of chemical energy from food into kinetic energy and thermal energy in 14.0 s?
a. 37.8 W
b. 0.2 W
c. 193 W
d. 5.2 W
e. none of these

You have been called to testify as an expert witness in a trial involving a head-on collision. car a weighs 1515 lb and was traveling eastward. car b weighs 1125 lb and was traveling westward at 44.0 mph. the cars locked bumpers and slid eastward with their wheels locked for 22.5 ft before stopping. you have measured the coefficient of kinetic friction between the tires and the pavement to be 0.750 . how fast (in miles per hour) was car a traveling just before the collision? (this problem uses english units because they would be used in a u. s. legal proceeding.)

Aparticle travels in a circular orbit of radius 21 m. its speed is changing at a rate of 23.1 m/s2 at an instant when its speed is 37.2 m/s. what is the magnitude of the acceleration (in m/s? ) of the particle?

An incident ray through the focal point of a spherical mirror will: reflect through the center of curvature. reflect back through the focal point. reflect parallel to the principle axis. reflect the same direction as the incident ray.