Answer:
The kinetic energy of the two stones is 320 J
Explanation:
Kinetic energy is the energy that a body possesses due to its movement. So it is the capacity or work that allows an object to go from being at rest, or still, to moving at a certain speed.
In other words, the kinetic energy of an object is that which is produced due to its motion and depends on its mass and velocity as follows:
[tex]Ec=\frac{1}{2} *m*v^{2}[/tex]
where the kinetic energy Ec is measured in joules (J), the mass m is measured in kilograms (kg) and the velocity v in meters/second (m/s).
In this case you know that a 20 kg curling stone is sliding in a positive direction at 4 m/s. So:
Replacing you have:
[tex]Ec_{1} =\frac{1}{2} *20 kg*(4\frac{m}{s}) ^{2}[/tex]
Ec₁= 160 J
A second curling stone slides at the same speed but in the opposite direction. So:
Replacing you have:
[tex]Ec_{2} =\frac{1}{2} *20 kg*(-4\frac{m}{s}) ^{2}[/tex]
Ec₂= 160 J
The kinetic energy of the two stones is calculated as:
Ec= Ec₁ + Ec₂
Ec= 160 J + 160 J
Ec= 320 J
The kinetic energy of the two stones is 320 J
