Answer: 10kg
Step-by-step explanation:
Given that:
Kinetic energy of puppy = 245J
Velocity of puppy = 7 m/s
mass of puppy = ?
Recall that kinetic energy is the energy possessed by a moving body. It is measured in joules, and depends on the mass and velocity of the moving body
i.e K.E = 1/2 x mass x (velocity)^2
245J = 1/2 x mass x (7 m/s)^2
245 = 0.5 x mass x 49
245 = 24.5 x mass
Mass = 245/24.5
Mass = 10kg
Thus, the mass of the puppy is 10kg