Question

A force of 1000N is needed to lift the hook of a crane at a steady velocity. The crane is than used to lift a load of mass 1000kg at a velocity of 5 m/s.The approximate power developed by the motor of crane used in lifting the hook and load is

Answer 1

Given:

Force of 1000 N is used to lift the hook of a crane at steady velocity. The crane is then used to lift a load of 1000 kg at a velocity of 5m/s.

To find:

Approx power developed by motor.

Calculation:

Power is a scalar quantity representing the instantaneous rate of work done with respect to time. It can also be calculated as a product of force and velocity.

Net force is the addition of force due to hook of crane and force due to load.

$\rm{power = net \: force \times velocity}$

$\rm{ = > power = (1000 + mg) \times 5}$

$\rm{ = > power = \{1000 + (1000 \times 10 )\} \times 5}$

$\rm{ = > power = 11000\times 5}$

$\rm{ = > power = 55000 \: watt}$

$\rm{ = > power = 55 \: kilo watt}$

So , final answer is :

$\boxed{ \large{ \sf{ power = 55 \: kilo watt}}}$

Answer 2

Answer:

as force is given=1000N

mass=1000kg and then now velocity is also givenwhich is 5m/s.

Explanation:

by using formula

P=F.V

=1000*5=5000watts or we can say 5kwatts