Which falling object has the least kinetic energy when it collides on the ground?

a
120 Kg of water falling at 12 m/s
b
12 Kg of water falling at 10 m/s
c
12 Kg of sand falling at 8 m/s
d
120 Kg of sand falling 12 m/s

1 answer

The answer is c, 12 Kg of sand falling at 8 m/s.

Kinetic energy is calculated using the formula 1/2mv^2, where m is the mass of the object and v is its velocity.

The kinetic energy of each object can be calculated as follows:

a) 1/2 x 120 Kg x (12 m/s)^2 = 8,640 J
b) 1/2 x 12 Kg x (10 m/s)^2 = 600 J
c) 1/2 x 12 Kg x (8 m/s)^2 = 384 J
d) 1/2 x 120 Kg x (12 m/s)^2 = 8,640 J

Therefore, object c has the least kinetic energy upon impact with the ground.