Answer:
1. 1800 W
2. $ 17.3
Explanation:
From the question given above, the following data were obtained:
Current (I) = 15 A
Voltage (V) = 120 V
Time (t) = 20 h per day
Duration = 31 days
Cost = 15.5 cents per kWh
1. Determination of the power.
Current (I) = 15 A
Voltage (V) = 120 V
Power (P) =?
P = IV
P = 15 × 120
P = 1800 W
Thus, 1800 W of power is required.
2. Determination of the cost per month (31 days).
We'll begin by converting 1800 W to KW.
1000 W = 1 KW
Therefore,
1800 W = 1800 W × 1 KW / 1000 W
1800 W = 1.8 KW
Next, we shall determine the energy consumption for 31 days. This can be obtained as follow:
Power (P) = 1.8 KW
Time (t) = 2 h per day
Time (t) for 31 days = 2 × 31 = 62 h
Energy (E) =?
E = Pt
E = 1.8 × 62
E = 111.6 KWh
Finally, we shall determine the cost of consumption. This can be obtained as follow:
1 KWh = 15.5 cents
Therefore,
111.6 KWh = 111.6 KWh × 15.5 cents / 1 KWh
111.6 KWh = 1729.8 cents
Converting 1729.8 cents to dollar, we have:
100 cents = $ 1
Therefore,
1729.8 cents = 1729.8 cents × $ 1 / 100 cents
1729.8 cents = $ 17.3
Thus, it will cost $ 17.3 per month to run the electric heater.
Answer: The correct answer is balanced force.
Explanation:
Balanced forces are balanced when the forces are acting equal in magnitude but opposite in direction. The balanced forces will not cause change in the speed of the object.
Unbalanced forces are unbalanced when the forces acting on the object are not equal in magnitude. The combined force is the difference between the forces. It will cause the change in the speed of the body.
Therefore, forces that are equal in size but opposite in direction are balanced.
Answer:
All these statement are true
Explanation:
Gravity will be acting like a centripetal force for the circular motion of object around earth, which makes it perpendicular to the velocity vector. In the case of elliptical motion, gravity can still be divided into 2 vectors, one parallel and the other perpendicular to the velocity. At the nearest point in elliptical motion, gravity is directly perpendicular to velocity just like in circular motion. At the farthest point, the potential energy is minimized and has been converted into kinetic energy. Therefore at this point the speed is greatest.
Answer:
a) 
b) 
Explanation:
The energy of the photon (E) for 
orbit of the hydrogen atom is given as:
where,
= 13.6 eV
n = orbit
a) Now for the transition from n = 4 to n = 5
b) Now for the transition from n = 5 to n = 6
Oi mate 3 electrons will be in tha 2nd energy level you silly willy.
