A object of mass 33 is dropped from a height of 85 meters. Calculate the average power developed by the object in falling through this distance.
Take g as 9.81 m/s^2

give the answer in watts to three significant figures


Sagot :

Power  =  Work done  /  Time taken.

Work done =  mgh
Mass, m = 33kg    ( Am presuming it is 33 kg).
h =  85 m.
Work done =  33 * 9.81* 85 =  27517.05  J.

Time taken.
Since object was dropped from height, it fell under gravity.
Using    H =  ut  +  (1/2) * gt^2.              u = 0.
               H =  1/2 gt^2.
               t  =   (2H/g) ^ (1/2)
               t  =  (2*85/9.81) ^ 0.5 =  4.1628 s.

Power  =    27517.05 / 4.1628 = 6610.23 Watts.
             =  6610 W  to  3 S. f.