<p>i don't understand the concept of work and energy, and my teacher teaches at like 100mph and expects us to know what he's talking about, when even the smartest kid in the grade comes in for help in the morning. maybe if you can help me with this question, then i can get the rest of the homework:</p>
<p>a sledge (who calls it that btw?) loaded with bricks has a total mass of 18.0kg and is pulled at constant speed by a rope inclined at 20.0degrees above the horizontal. The sledge moves a distance of 20.0 m on a horizontal surface. The coefficient of kinetic friction between the sledge and the surface is 0.500. (a) What is the tension in the rope? (b) How much work is done by the rope on the sledge? (c) What is the mechanical energy lost due to friction (idk if my class even went over part c)</p>
<p>any help would be appreciated.</p>