A dog runs down a hill. The dog has a mass of 25 kilograms and has 450 J of energy. What is the dog's velocity?

Question

Quizplus · Accepted Answer

Kinetic Energy is the energy an object possesses because of its velocity. Any object that is in motion is using kinetic energy: a child running, a thrown ball, someone skiing down a hill, or a book falling off of a shelf. This is why the equation takes into account the object's mass and the rate at which they are traveling (their velocity). KE = ½ x mv² KE = Kinetic energy (expressed in Joules - J) m = mass (expressed in kilograms) v² = velocity (expressed in meters per second squared) To find the velocity we must isolate it: 2 x KE = 2 x ½ x mv² 2 x KE = mv² 2 x KE / m = mv² / m 2 x KE / m = v² m = 25 kg KE = 450 J v² = 2 x 450 J / 25 kg = 36 m²/s² We then take the square root of this and v = 6 m/s *Don't forget that the velocity is squared*

A Dog Runs Down a Hill