Saturday

April 18, 2015

April 18, 2015

Posted by **Danny** on Tuesday, February 26, 2013 at 10:03am.

world, operating in Switzerland, can slowly

raise a load of 6000 tonne to a height of 12 m.

(1 tonne = 1000 kg)

The acceleration of gravity is 9.81 m/s2 .

How much work is done by the crane?

Answer in units of MJ

I found it by using Work = mass* acceleration* distance

1) converted 6000 tones to kilograms and I got 6000000kg thus,

2) work = (6000000kg)*(9.81m/s^2)*(12m)=706320000J

3)Then I converted 706320000j to MJ

706320000/10^6=70632 MJ

002 (part 2 of 2) 5.0 points

If it takes 3 min to lift the load at constant velocity to this height, find the power developed

by the crane.

Answer in units of MW.

please help me I have tried it 3 times and it's wrong. Please explain so I can understand how to go about this problems.

- Physics -
**Henry**, Thursday, February 28, 2013 at 12:28pmMass=6*10^3tons * 1*10^3kg/ton=6*10^6kg.

Work = F*h = mg*h.

Work = 6*10^6*9.81 * 12=706.3*10^6 J. =

706.3 MJ.

P = Work/T = 706.3MJ/180s. = 3.92 MJ/s.=

3.92 MW.

**Answer this Question**

**Related Questions**

Physics. PLEASE HELP!! - NOTE: 1 MJ = 106J. One of the most powerful cranes in ...

Physics matter and its properties - A circular metal column is to support a load...

Math - Calculate the mass of water in kg and tonne contained in a rectangular ...

Physics - Hi Can someone check and advise on this potential energy of 2 tonne of...

physics - A truck of mass 1.0 tonne moving at 4.0 m/s catches up and collides ...

physics - A crane lifts 1 tonne of concrete through a height of 25 m. How much ...

Maths / physics - Calculate the rest mass (In grams) of an object whose rest ...

Science - Which one is longer mts (metre-tonne-second) or km (kilometre)?

physics - The energy needed to raise a load of mass 10 kg is 100 J. The height ...

physics - Determine how much water would be present in a 10 tonne sample of ...