Question

The kinetic energy (in joules ) of a moving object can be calculated from the expression 1/2mv to the second power, where m is the mass of the object in kilograms and v is it’s speed in meters per second. Find the kinetic energy of a 0.145-kg baseball that is thrown at a speed of 40 meters per second. E = ______ joules

Answer 1

E = 1/2 m v^2

E = 1/2 (0.145) (40)^2

E = 0.0725 x 1600

E = 116 kg m^2/s^2

1 joule = 1 kg m^2/s^2

so here E in joules is 116 joules

so E = 116 joules