Question

A variable force of 4xâ2 pounds moves an object along a straight line when it is x feet from the origin. calculate the work done in moving the object from x = 1 ft to x = 12 ft. (round your answer to two decimal places.) 3.67 correct: your answer is correct. ft-lb

Answer 1

Our variable force is given by 4a^(-2). We shall integrate the force and find the work done at the respective points. Intregal (4a^(-2)) = 4 integral (a^(-2)) So -4(a^(-2+1)) = -4a^(-1) = -4/a At point 1 and 12 we have -4/a -4/12 - (-4/1) = - This gives us -1/3 + 4 = 3.67