Answer:
7 m/s
Explanation:
To solve this problem you must use the conservation of energy.
[tex]K1 +U1=K2+U2[/tex]
That math speak for, initial kinetic energy plus initial potential energy equals final kinetic energy plus final potential energy.
The initial PE (potential energy) is 0 because it hasn't been raised in the air yet. The final KE (kinetic energy) is 0 because it isn't moving. This gives the following:
[tex]KE1= \frac{1}{2}mv^{2}}[/tex]
[tex]PE2=mgh[/tex]
K1=U2
[tex]\frac{1}{2} mv^{2} =mgh[/tex]
Solve for v
[tex]v=\sqrt{2gh}[/tex]
Input known values and you get 7 m/s.
