Explanation:
Problem 2.5, mixing dough.
Please note dimensional units and standard formulas for energies.
Input:
Electrical energy = VIT = 110 V * 1.5 A * 5 min. * 60 s/min = 49500 joules = 49.5 kJ
Output:
Warming of dough = mCΔT = 1 kg * 4.2 kJ/(kg*K) * 5 deg.K = 21 kJ
Dissipation of energy = remainder of input energy = (49.5-21) kJ = 28.5 kJ
Fraction of energy converted to energy of dough = 21 kJ / 49.5 kJ
= forty-two percent (to the nearest percent)
The last item, dissipation of energy could be attributed to:
1. Loss in efficiency of mixer in the form of mechanical friction, heating up due to resistance of motor circuit, etc.
2. Loss in mechanical mixing of dough due to friction between mixer paddle and dough in the form of heat, part of which stays with dough (thus heating up of dough), and the remainder heats up the dough container, loss of heat to environment, air, heat of vaporization of water content of dough, etc.
Answer:
The statement is TRUE
Explanation:
computer programs like spreadsheets can be used to help organize and analyze data. Regression Analysis can be carried out in Excel to determine the relationship between two quantitative variables.
Answer:
B.7.5m/s2
Explanation:
average acceleration=change invelocity/time taken
a=(60-30)/4
=7.5m/s2
Velocity increases with speed
Answer:
We conclude that if a flat piece of paper or blowing ball is dropped from the same height, They would hit the ground at the same time.
Thus,
option a) is correct.
Explanation:
When there is no air in the space, it is basically a vacuum.
- In other words, the vacuum can be termed as a 'space devoid of matter'.
So, when there is no air in space, it means there is no force that can act on the body.
- Therefore, no matter what objects (heavy or light) we may drop from the same height, they would all hit the ground at the same time.
As there is no force that can act on an object in the vacuum, it means every object in the vacuum seems to stand still while falling.
Therefore, we conclude that if a flat piece of paper or blowing ball is dropped from the same height, They would hit the ground at the same time.
Thus,
option a) is correct.