Answer:
B) Ball B has greater kinetic energy.
C) Both the balls have same amount of potential energy.
Explanation:
Since both the balls are dropped therefore their initial kinetic energy is zero.
Finally both the balls reach to ground therefore their potential energy will be same and equal to zero.
Potential Energy = mgh ; m : mass of object
g : acceleration due to gravity = 9.8 m/s^2
h : height of object from ground
Kinetic Energy = [tex]\mathbf{\frac{1}{2}mv^{2}}[/tex] ; m : mass of object
v : speed of object
Mechanical Energy = Potential energy + Kinetic Energy = Constant
Mass of Ball A = Mass of Ball B = m = 180 g = 0.18 kg
Height of ball A initially = [tex]\mathrm{h_{A}}[/tex] = 3 m
Height of ball B initially = [tex]\mathrm{h_{B}}[/tex] = 4 m
Mechanical Energy of Ball A = Potential energy initially + Kinetic Energy initial = Potential energy finally + Kinetic Energy finally = 0.18 × 9.8 × 3 + 0 = 5.292 J = Kinetic energy finally of ball A
Mechanical Energy of Ball B = Potential energy initially + Kinetic Energy initial = Potential energy finally + Kinetic Energy finally = 0.18 × 9.8 × 4 + 0 = 7.056 J = Kinetic energy finally of ball B
Therefore, Ball B has greater kinetic energy
