Answer:
Part a)
P = 13.93 kW
Part b)
R = 8357.6 Cents
Explanation:
Part A)
heat required to melt the aluminium is given by
here we have
Since this is the amount of aluminium per hour
so power required to melt is given by
Since the efficiency is 85% so actual power required will be
Part B)
Total energy consumed by the furnace for 30 hours
now the total cost of energy consumption is given as
Answer:
B
Explanation:
kinetic energy (KE) is the energy possessed by moving bodies. It can be expressed as:
KE = m
Where: m is the mass of the object, and v its speed.
For example, a stone of mass 2kg was thrown and moves with a speed of 3 m/s. Determine the kinetic energy of the stone.
Thus,
KE = x 2 x
= 9
KE = 9.0 Joules
Assume that the speed of the stone was 4 m/s, then its KE would be:
KE = x 2 x
= 16
KE = 16.0 Joules
Therefore, it can be observed that as speed increases, the kinetic energy increases. Thus option B is appropriate.
Answer:
50 J
Explanation:
The net force acting on the box is given by the algebraic sum of the two forces, so:
The net work done on the box is equal to (assuming the net force is parallel to the displacement of the object)
where
F = 5 N is the net force on the object
d = 10 m is the displacement of the object
Substituting,
Answer:
13.875 T
Explanation:
Parameters given:
Length of solenoid, L = 2.5 cm = 0.025 m
Radius of solenoid, r = 0.75 cm = 0.0075 m
Number of turns, N = 25 turns
Current, I = 1.85 A
Magnetic field, B, is given as:
B = (N*r*I) /L
B = (25 * 0.0075 * 1.85)/0.025
B = 13.875 T
Answer:
D. Burning paper
Explanation:
physical change is just changing the way it looks
chemical change is changing the properties of the object or thing
melting ice is just changing the way it looks it still has the same atoms and elements.
when you burn something it will change the properties of the atoms in the object