1) Determine the variation of mechanical energy of the hailstones during impact on the ground. 2) Assuming all the lost mechanical energy is transferred to the hailstone determine the mass of ice that melts during the impact. We have : $1/2mv_f^2 -1/2mv_i^2 = 0- 1/2 ( 0.001) ( 18) ^2 =-0,162 joul= -Q$
What mass of ice is needed to cool 60g of water from 45°C to 20°C? It depends on what temperature your ice is. The Ice can absorb temperature ( energy) in two ways. Being colder than the water. Ice at -100C is colder than ice at -1C. So to answer your homework question, you need to assume a temperature for your ice.
Essentially the concept here is the fact that after the ice melts, the mixture will have a temperature T that will be lower than the initial water temperature (40° C). And according to the laws of thermodynamics, the heat gained by the ice will be equal to the heat lost by the water. Now the ice will gain heat in three steps viz.
This heat was gained by the ice. The ice goes through two steps - it melts to make water at 0 deg C and then this melted ice warms up to 25 deg C. This expression = total heat lost from first part - you only have one unknown - so you can solve the equation.
Determine the mass of the ice cubes by subtracting the mass of the cup and water from the mass of the cup, water and ice cubes together. If the cup, water and ice together weighed 110.4 g, then the mass of the ice cubes was 110.4 g - 103.4 g = 7.0 g.
334 JoulesIn order to melt ice of 0°C to water of 0°C, a high amount of energy is needed, equivalent to 334 Joules for each gram. The same amount of energy is released in the atmosphere or ground when water freezes to ice.
- To melt 1 gram of ice requires 80 calories. (A calorie is defined as the amount of energy needed to raise one gram of water 1°C.) - The change from liquid to ice is called solidification. This process will release 80 calories per gram.
Because the ice is just melting. It is still the same amount of water, but it's just changing from a solid to a liquid. It should have the same mass.
333,000 JoulesProblem 2 - The Latent Heat of Fusion for water is 333 Joules/gram. How many Joules of energy do you need to melt all the ice into a pure liquid along the path from B to C on the graph? Answer: For 1 kilogram of ice ,which equals 1000 grams, we need 333 Joules/gram x 1000 grams = 333,000 Joules.
Energy is required to melt a solid because the cohesive bonds between the molecules in the solid must be broken apart such that, in the liquid, the molecules can move around at comparable kinetic energies; thus, there is no rise in temperature.
The specific heat of melting of ice is 334 J/g, so melting 100g of ice will take 33,400 J.
Key Takeaways: Heat of Fusion for Melting IceHeat of fusion is the amount of energy in the form of heat needed to change the state of matter from a solid to a liquid (melting.)The formula to calculate heat of fusion is: q = m·ΔHfMore items...•
Thus the “15° calorie” (also called the gram-calorie, or small calorie) was defined as the amount of heat that will raise the temperature of 1 gram of water from 14.5° to 15.5° C—equal to 4.1855 joules.
This is because the ice floats and some of it is above the water line before it melts. This ice is displacing a volume of water corresponding to the mass of the ice. When the ice melts it will then occupy the same volume of water which corresponds to the mass of the water it displaced before it was melted.
Comparison of:Liquid waterIceMass = 100 gMass = 100 gVolume = 100 mLVolume = ? mLDensity = 1.0 g/mLDensity = 0.92 g/mL
Changing states of matter and energy A block of ice is solid water. When heat (a form of energy) is added, the ice melts into liquid water. It has reached its melting point – 0°C. Continue to apply heat, and the water will turn into water vapour, which is water in its gaseous state.
It is much easier to melt ice if heat is applied to it while it takes a much longer time to completely vaporize the same mass of water.
167000 joules(2)✎ 167000 joules of energy are required to melt 0.5kg of ice.
It takes longer to boil water than to melt ice because of the difference in the amount of heat required to overcome the forces of attraction by keeping the temperature constant during this time. This is the reason it takes longer in boiling than in melting.
Key Takeaways: Heat of Fusion for Melting IceHeat of fusion is the amount of energy in the form of heat needed to change the state of matter from a solid to a liquid (melting.)The formula to calculate heat of fusion is: q = m·ΔHfMore items...•