A potential energy function for a two- dimensional force is of the form U = ax3y + bx , where a= 5.63J/m4 and b= −9J/m. Find the magnitude of the force that acts at the point (x, y) for x = 84 m, y = 47 m.

A 17.9 kg block is dragged over a rough, horizontal surface by a constant force of 111 Nacting at an angle of angle 31.1◦above the horizontal. The block is displaced 60 m and the coefficient of kinetic friction is 0.152. Find the work done by the 111 N force. The acceleration of gravity is 9.8 m/s2.Answer in units of J. Find the magnitude of the work done by the force of friction.Answer in units of J What is the sign of the work done by the frictional force?1. positive2. negative3. zero Find the work done by the normal force.Answer in units of J What is the net work done on the block?Answer in units of J.

1.49 x 103 J of work are done by the force F (magnitude = 47.4 N) in moving the suitcase a distance of 43.3 m. At what angle θ is the force oriented with respect to the ground?

A cable exerts a constant upward tension of magnitude 2.70 ✕ 104 N on a 2.40 ✕ 103 kg elevator as it rises through a vertical distance of 2.90 m. HINT (a) Find the work done by the tension force on the elevator (in J).  J (b) Find the work done by the force of gravity on the elevator (in J).  J