B. It is the heat required to change a gram of substance from solid to liquid
Answer:
a solution: for example when sugar is dissolved in water it becomes a sugar solution
Answer:
a) 250 N
b) 50 N
c) 5000 J
d) 4
e) 3.33
Explanation:
Given that weight of piano (
) = 1000 N, distance moved by pulley (
) = 5 m and the rope used (
) =20 m
a) The effort applied (
) if it was an ideal machine is:
b) If the actual effort = 300 N
The force to overcome friction = actual effort - = 300 - 250 = 50 N
c) Work output = 
d) ideal mechanical advantage (IMA) = 
e) Input force = 300 N, Therefore:
actual mechanical advantage = / input force = 1000 / 300 = 3.33
Answer:
Mass of the water is equal to the mass of ice
Explanation:
When ice melts, the mass remains the same even though its volume decreases leading to a decrease in density of water.
The mass remains the same because according to the law of conservation of mass, mass can neither be created nor destroyed. Since mass is neither created nor destroyed in the process of melting, the mass of water must remain the same.
