54J
You calculate kinetic energy by the equation.
KE= 1/2mv^2
m= mass
v= velocity
then we have
KE = 1/2 x 3 x 6^2
KE = 1/2 x 3 x 36 = 54J
In a non accelerated frame, also called inertial frame, when no additional forces are acting upon the body.
For instance, a scale in free fall will not record the weight, but zero, like the astronauts. But also, if someone is pulling the object or pushing it, the scale will record some other value.
As we know that power is defined as rate of work done
so we will have
so in order to increase the power as per above formula we know that either we need to increase the work or we need to decrease the time to complete that work
So here the correct answer will be
increase the work being done or decrease the time in which the work is completed.
Explanation:
2) C would need the least effort, because the longer the effort distance, the least the effort applied.
