A helter-skelter ride at a fairground consists of a spiral-shaped slide that people slide down on mats. The top of the slide is $7 \mathrm{m}$ higher than the bottom. The average frictional resistance is $50 \mathrm{N}$. A boy of mass $60 \mathrm{kg}$ slides down the helter-skelter, starting from rest. At the bottom of the ride the boy has speed $10 \mathrm{m}{ \mathrm{s}}^{-1}$.

Find the length of the slide. (Use: $g=10 \mathrm{m} {\mathrm{s}}^{-2}$)

A helter-skelter ride at a fairground consists of a spiral-shaped slide that people slide down on mats. The top of the slide is $7 \mathrm{m}$ higher than the bottom. The average frictional resistance is $50 \mathrm{N}$. A boy of mass $60 \mathrm{kg}$ slides down the helter-skelter, starting from rest. At the bottom of the ride the boy has speed $10 \mathrm{m}{ \mathrm{s}}^{-1}$.

Work out the amount of mechanical energy that has been lost. (Use: $g=10 \mathrm{m} {\mathrm{s}}^{-2}$)

A helter-skelter ride at a fairground consists of a spiral-shaped slide that people slide down on mats. The top of the slide is $7 \mathrm{m}$ higher than the bottom. The average frictional resistance is $50 \mathrm{N}$. A boy of mass $60 \mathrm{kg}$ slides down the helter-skelter, starting from rest. At the bottom of the ride the boy has speed $10 \mathrm{m}{ \mathrm{s}}^{-1}$.

What form of energy has most of this loss of mechanical energy been changed into? (Use: $g=10 \mathrm{m} {\mathrm{s}}^{-2}$)