1. An object of mass 0.23 kg is initially at the origin and is acted on by the sole force F=(0.50 N)i. After a certain amount of time, the object is ast a position r=(0.80 m)i. What is the canged in the object's kinetic energy?

2. 74 gram ball is tossed straight up in the air, rises to a maximum point, then falls bacck until it is .6 m below the posoition of the hand that tossed it up. A second ball is simply dropped from the same hand position and also lands 0.60 m below that position. What is the net work done by gravity in the two cases?

3. The net force acrting on a particle depends on the position of the particle on the x-axis according to the relation F=Fo +Cx, w here Fo=5N and C=-2N/m. The particle is initially at rest at the point x=0 m when the force begins to act.

(a) Calculate the work done by the force when the particle reaces x values of 1, 2, 3, and 4 m.

(b) Determine any positions (other than at x=0 m) where the work done is zero.

(c) Is the force conservative?

4. Teh maximum power of a particular horse is 1 hp. With what speed can this horse pull a sled on level ground if the weight of the sled with its load is 5000 N and the coefficient of kinetic friction is Mk=0.03? What is the maximum speed on a 5 degree upward incline?