how fast would an 80 kg man need to run in order to have the same kinetic energy as an 8.0g bullet fired at 400m/s?

Question

rvc · Answer

what is the formula of Kinetic energy

rvc · Answer

$$\rm K.E=0.5mv^2$$

rvc · Answer

since both must have same KE so equate them

rvc · Answer

$$\rm 0.5m_1v_1^2=0.5m_2v_2^2~~1~represents~about~the~man$$

anonymous · Answer

that's it you sure?

anonymous · Answer

The problem states that their kinetic energies are the same. By setting them equal to each other, we are mathematically making the same statement that they are the same. From there, you can plug in whatever you are given and calculate what you are looking for, which in this case, is the velocity of the man.

anonymous · Answer

So yes, @rvc 's method is correct.

unklerhaukus · Answer

solve for $v_1$, then plug in the values