A loaded sledge travels from the top of a snow-covered slope to the bottom.
| Quantity | Value |
|---|---|
| total mass of the sledge and its load | 50 kg |
| motion at the top of the slope | at rest |
| vertical drop | 8.0 m |
| speed at the bottom of the slope | 10 m/s |
| gravitational field strength, ggg | 10 N/kg |
The following equations may be used.
ΔEg=mgΔh\Delta E_{\mathrm{g}}=mg\Delta hΔEg=mgΔh
Ek=12mv2E_{\mathrm{k}}=\dfrac{1}{2}mv^2Ek=21mv2
The energy-accounting table for the journey is incomplete.
| Energy change during the journey | Energy in J |
|---|---|
| transferred out of the gravitational store | XXX |
| transferred to the kinetic store | YYY |
| dissipated | ZZZ |
Calculate the value of X X\,X in the energy-accounting table.
Calculate the value of Y Y\,Y in the energy-accounting table.
Use your answers to (a) and (b) to calculate ZZZ.
Suggest one reason why Z Z\,Z would be greater if the snow were rougher.