Answer:
Hey :)
Explanation:
Work is a net force applied through a distance in order to displace an object, commonly abbreviated as W. A net force is the sum of all forces acting on an object. Work is mass times acceleration and distance so to find out the work you simply calculate the acceleration of the box being brought in. Next find the distance it was carried to get in the house. Then find out the mas of the box and finally multiply those sums together to get the amount of work put in to bring the package inside.
hope this helps :) xo
-- Heat will flow out of the warm aluminum and into the cool water.
-- The temperature of the aluminum will fall and the temperature of the water will rise.
-- Eventually, everything in the container will settle at the same temperature, and temperatures will stop changing.
-- The final "equilibrium" temperature will be a little less than 40°C (the average of 60° and 20°), because the specific heat of the aluminum is about 8% less than the specific heat of the water. So when some quantity of heat flows from the aluminum to the water, the temperature of the water rises a little less than the temperature of the aluminum falls.
Answer:
A. 873 kJ
B. -436.5 kJ
Explanation:
Parameters given:
Volume of water = 3m³
Density of water = 1000 kg/m³
Height above the earth, h = 30m
The gravitational potential energy, PE, is given as:
PE = m*g*h
Where m is mass and g is acceleration due to gravity.
Mass, m, can be obtained:
Density = mass/volume
Mass = density * volume
Mass, m = 3 * 1000 = 3000kg
=> Potential ENERGY, PE = 3000 * 9.7 * 30
PE = 873000 J = 873 kJ
B. If the height is decreased by 15m,
h = 30 - 15 = 15m
PE = 3000 * 9.7 * 15
PE = 436500 J = 436.5 kJ
Change in PE will be:
ΔPE = PEfinal - PEinitial
ΔPE = 436.5 - 873
ΔPE = -436.5 kJ
