X = 8
because 8 x 2 = 16
16 - 9 = 5
5 x 3 = 15
Answer:
30 km/h car
Step-by-step explanation:
From analysis the car traveling at 30 km/h has greater kinetic energy
we can deduce it from the expression of kinetic energy which is
Assuming the mass m= 1 kg
For the 30 km/h
For the 15 km/h
Though the kinetic energy is a function of mass and velocity, but from our analysis the faster moving object has more KE