More M2 Power help please!

14

I've done the first couple of parts but need help on the rest!!

A boat of mass 1200kg is winched a distance 30m up a flat beach inclined at 10 degrees to the horizontal.

Initially a very approximate model is used in which all resistances are neglected.
(i) Calculate work done. 61263.08
(ii) Given that the process takes 2 minutes and that the boat moves at a constant speed, calculate the power of the winch motor. 510.53

A better model takes account of the resistance of the beach to the motion. Assuming that the winch motor develops a constant 4.5kW, the resistance of the beach on the boat is a constant 5kN and the boat moves at a constant speed,
(iii) calculate how long the winching will take :confused:

(iv) show that if the winch cable suddenly broke off at the boat whilst the winching was in progress, the boat would come to rest in about 35mm :confused:

thanks

Reply 1

technicolour

3

Well for iii) you need to calculate the work done from pulling up the boat. Since you already know the power, you can then calculate the time taken.
For iv) you need to calculate the speed at which the boat moves from the distance and the time taken, and the rest is equations of motion.

Reply 2

jenny28

OP

14

technicolour

Well for iii) you need to calculate the work done from pulling up the boat. Since you already know the power, you can then calculate the time taken.
For iv) you need to calculate the speed at which the boat moves from the distance and the time taken, and the rest is equations of motion.