Answer:
speed of the car = 8 m/sec
Explanation:
For Lorry
Mass of the lorry m = 4000 kg
Speed of the lorry v= 4 m/sec
Kinetic energy of the lorry = [tex]\frac{1}{2} mv^{2}[/tex] =[tex]\frac{1}{2} 4000\cdot4^{2}[/tex] =32000 J
It is given that Kinetic energy of car = Kinetic energy of lorry
Hence, Kinetic Energy of car = 32000 J
For car
Mass of the car = 1000 kg
Suppose the speed of the car =[tex]v_c\ m/sec[/tex]
Kinetic energy of the car = [tex]\frac{1}{2} mv_c^{2}[/tex] =32000 J
[tex]\frac{1}{2}1000\cdot v_c^{2}[/tex] =32000
[tex]v_c^{2} =64\\v_c=8[/tex]m/sec
Hence speed of the car = 8 m/sec
