Respuesta :
here we can say that since the hill is friction less So total energy is now conserved
we can use the energy conservation principle now
[tex]U_i + KE_i = U_f + KE_f[/tex]
here we can say that initial KE is zero as the child and sled is at rest
and the final potential energy will also be zero as the child will reach the bottom
So here we can say
[tex]mgh + 0 = 0 + \frac{1}{2}mv^2[/tex]
[tex]v = \sqrt{2gh}[/tex]
[tex]v = \sqrt{2*9.8*8.38}[/tex]
[tex]v = 12.8 m/s[/tex]
so final speed will be 12.8 m/s