Answer:
The speed is 10 m/s
Step-by-step explanation:
Th mass if the rock = 100 g = 0.1 kg
The kinetic energy = 5.0 J
speed of the rock = ?
The kinetic energy of the rock is given by the equation
E =

where
m is the mass of the rock
V is the velocity of the rock
substituting, we have
5 =

= 5/0.05 = 100
v =
= 10 m/s