Answer:
Velocity = 20.3 [m/s]
Explanation:
This is a typical problem of energy conservation, where potential energy is converted to kinetic energy. We must first find the potential energy. In this way, we will choose as a reference point or point where the potential energy is zero when the carrriage rolls down 21 [m] from the top of the hill.
[tex]E_{p} =m*g*h\\ where:\\m = mass = 25[kg]\\g = gravity = 9.81 [m/s^2]\\h = elevation = 21 [m]\\E_{p} =potential energy [J]\\E_{p} =25*9.81*21=5150[J][/tex]
Now this will be the same energy transformed into kinetic energy, therefore:
[tex]E_{p}=E_{k} = 5150[J]\\E_{k} =0.5*m*v^{2} \\where:\\v=velocity [m/s]\\v=\sqrt{\frac{E_{k}}{0.5*25} } \\v=20.3[m/s][/tex]
