Answer:
Q = 282,000 J
Explanation:
Given that,
The mass of liquid water, m = 125 g
Temperature, T = 100°C
The latent heat of vaporization, Hv = 2258 J/g.
We need to find the amount of heat needed to vaporize 125 g of liquid water. We can find it as follows :

or
Q = 282,000 J
So, the required heat is 282,000 J
.
Answer: (B) There is complete destructive interference between the incoming and reflected waves
Explanation:
For example, if you pluck a guitar the waves will travel back and forth. They consist of nodes and anti-nodes. It is created, when the wave traveling to one side and bounces of the other end and comes back. As it travels to the other side, it is reflected thus, comes back. So standing waves occurs when there is interference.
When the wave is produced, the points where the string is not moving are called nodes and where they are moving are called anti-nodes. The positions where nodes are produced, destructive interference occurs and where anti-nodes are produced, constructive interference occurs
Answer:
a)

b) 
Explanation:
The net force on the car must produce the centripetal acceleration necessary to make this circle, which is
. At the top of the circle, the normal force and the weight point downwards (like the centripetal force should), while at the bottom the normal force points upwards (like the centripetal force should) and the weight downwards, so we have (taking the upwards direction as positive):

Which means:

The limit for falling off would be
, so the minimum speed would be:

Answer:
Explanation:
Total Resistance, Rt = (0.35 + 0.002 + 5200 + 0.5 + 0.008 + 1100) = 6300 ohms
a) Capacity of transformer, Pt = 150KVA = 150,000 W
Input Voltage, Vp = 2.8 KV = 2800 V
Current, Ip = 150000/2800 = 53.57 A
Input impedance, Zp = Vp/Ip = 2800/5357 = 52.27 ohms
b) i) Input current = 53.57 A
ii) Voltage, V = Ip * Rt = 53.57 X 6300 = 337.5 KV
iii) Power, P = I² * Rt = (53.57)² X 6300 = 18.08 MW
iv) Power factor = 0.83