<u>Answer</u>
A. Metals A and metals B
<u>Explanation</u>
Heat transfer takes place whenever there is temperature difference. When two bodies of different temperatures are brought together, heat energy will move from one body to the other until equilibrium temperature is reached.
In our case, heat transfer will take place in all four metals.
Metal A will transfer heat to the water since it's temperature is higher than that of water.
Metal B will also transfer heat to the water since it's temperature is higher than that of water.
Metal C will get heat from the water since it's colder than the water.
Metal D will also get heat from the water since it is colder than water.
To be able to answer this item, we are to calculate the power that the machine could deliver from hp to kW.
(45 hp)(746 W/1 hp) = 33570 W
Power is the amount of energy delivered at a certain period.
t = (6.20 x 10^2 J)/ (33570 kJ/s)
t = 0.01845 s
Answer: 6250 joules
Explanation:
The work needed to lift an object of mass M by a height H is equal to:
w = M*g*H
where h = 10m/s^2
then the total work that he did is equal to the sum of the work for every stone:
W = (100kg*g*H) + (120kg*g*H) + (140kg*g*H) + (160kg*g*H) + (180kg*g*H)
= (100kg + 120kg + 140kg + 160kg + 180kg)*g*H
= (500kg)*g*H
and now we can repalce g by 10m/s^2 and H by 125cm
But you can notice that we have two different units of distance, so knowing that 100cm = 1m
we can write H = 125cm = (125/100) m = 1.25 m
Then we have:
H = 500kg*10m/s^2*1.25m = 6250 J
Work-Energy :W = 1/2 m ( Vf^2 -Vo^2 )
Vo = 24.0 m/s Initial speed
Vf = 27.5 m/s Final speed
W = 1/2 m ( Vf^2 -Vo^2 )
160 kj = 1/ 2 m ( 27.5^2 -24.0 ^2)
160kj = 4680 x m
convert kilo joules to jeoules 160000 j = 4689 xm
m = 160000 j/4689
m = 34.18 kg
Answer:
There will be two forces acting on her: Gravitational force and Air resisitence
