In 12 words no symbols or units identify the quantity matchi

In 1-2 words (no symbols or units), identify the quantity matching each description: (a) Rate at which work is done: (b) Energy of motion: (c) Time for one complete rotation: (d) Rate at which angular velocity changes: 3. A large steel beam is being raised by a cable. (a) If the tension in the cable is 5670 N, and that force does 34 000 J = 34 kJ of work on the beam, how far did the beam rise? (b) Calculate the power developed by the tension force if it lifted the beam in 8.9 s.

Solution

For a force F acting on a body over a distance of S, the work done is given as the cross product of the force and the displacement.

That is, W = F.S

a.) Now, for the given situation, we have the displacement happening in the direction of the force. Also, the work done is 34000 Joules with the force of 5670 N

Hence, 34000 = 5670 x S

or, S = 5.9965 m

Therefore the beam rises by 5.9965 metres

b.) We know that the relation between work and power is given as:

Power = Work / Time

or, Power = 34000 / 8.9 = 3820.2247 Watts