Question

At what speed does a 1200 kg compact car have the same kinetic energy as a 1.80Ã104 kg truck going 22.0 km/hr

Answer 1

Kinetic Energy of truck:

Given: Mass m = 1.80 x 10⁴ Kg;    Velocity V = 22 Km/hr  or 6.11 m/s

K.E = 1/2 mv²
 
       = 1/2 (1.80 x 10⁴ Kg)(6.11 m/s)²

K.E = 335,989 J

At what speed for a compact car to have the same Kinetic energy?

Compact car

Given: Mass m = 1200 Kg

K.E = 1/2 mv²

V = √2 K.E/m

V = √2(335,989 J)/1200 Kg

V = 23.66 m/s  Answer