If a man does 4500 J of work from a high rise building of 10 m, what is his mass?

Explanation:

The potential energy (Ep) = 4500 J

Ep = m. g. h

=> m = Ep/(g.h)

m = 4500/(10×10)

= 4500/100

= 45

so, the mass = 45 kgs

Heat Flow Rate : ( About ) 87 W

Explanation:

The heat flowing out of the system each minute, will be represented by the following equation,

Q( cup ) + Q( water ) = m( cup ) c( al ) ΔT + m( w ) c( w ) ΔT

So as you can see, the mass of the aluminum cup is 150 grams. For convenience, let us convert that into kilograms,

150 grams = .15 kilograms - respectively let us convert the mass of water to kilograms,

800 grams = .8 kilograms

Now remember that the specific heat of aluminum is 900 J / kg K, and the specific heat of water = 4186 J / kg K. Therefore let us solve for " the heat flowing out of the system per minute, "

Q( cup ) + Q( water ) = .15 ( 900 J / kg K )   1.5 + .8 ( 4186 J / kg K ) 1.5,

Q( cup ) + Q( water ) = 5225.7 Joules

And the heat flow rate should be Joules per minute,

5225.7 Joules / 60 seconds = ( About ) 87 W