Question

The amount of mechanical kinetic energy possessed by a 0.25-kilogram ball rolling at a speed of 2.5 meters per second is ____ joules.

a. 0.31
b. 0.63
c. 0.78
d. 1.6

Answer 1

The kinetic energy of a 0.25-kilogram ball rolling at 2.5 meters per second is calculated as 0.78 joules, using the formula for kinetic energy KE = ½mv².

Step-by-step explanation:

The amount of mechanical kinetic energy (KE) possessed by a rolling ball can be calculated using the formula for kinetic energy, which is KE = ½mv², where m is the mass of the object and v is the velocity at which it is moving. In this case, for a 0.25-kilogram ball rolling at a speed of 2.5 meters per second, we can calculate the kinetic energy as follows:

KE = ½ * 0.25 kg * (2.5 m/s)² = ½ * 0.25 * 6.25 = 0.78125 J

Thus, rounding to two decimal places, the kinetic energy of the ball is 0.78 joules, which corresponds to option c. 0.78.