Paper 4 October/November 2007 MATHEMATICH (9709/4) A Levels
لطفا برای اطمینان از عملکرد و تجربه بهتر از مرورگرهای مدرن و به روز مانند کروم یا فایرفاکس استفاده کنید.

A lorry of mass $15000{\text{ }}kg$ climbs a hill of length $500{\text{ }}m$ at a constant speed. The hill is inclined at ${2.5^ \circ }$ to the horizontal. The resistance to the lorry’s motion is constant and equal to $800{\text{ }}N$.
a) Find the work done by the lorry’s driving force.
On its return journey the lorry reaches the top of the hill with speed $20{\text{ }}m{\text{ }}{s^{ - 1}}$ and continues down the hill with a constant driving force…