Answer: 2940 J
Explanation: solution attached:
PE= mgh
Substitute the values:
PE= 10kg x 9.8 m/s² x 30 m
= 2940 J
The width is 2.5 cm long and could not be the right answer
Answer:
1) It expresses the rate (top speed) at which it can move with time.
2) P = 20 W
3) h = 18 km
Explanation:
1) Power is the rate of transfer of energy.
⇒ Power = 
i.e P = 
Thus a car's engine power is 44000W implies that the engine of the car can propel the car at this rate. This expresses the rate (top speed) at which it can move with time.
2) m = 400g = 0.4 kg
t = 20 s
h = 100m
g = 10 m/
P = 
= 
= 
P = 20 W
3) u = 600 m/s
g = 10 m/
From the third equation of free fall,
=
- 2gh
V is the final velocity, U is the initial velocity, h is the height.
0 =
- 2 x 10 x h
0 = 360000 - 20h
20h = 360000
h = 
= 18000
h = 18 km
The maximum height of the bullet would be 18 km.
The resonant frequency of a circuit is the frequency
at which the equivalent impedance of a circuit is purely real (the imaginary part is null).
Mathematically this frequency is described as

Where
L = Inductance
C = Capacitance
Our values are given as


Replacing we have,



From this relationship we can also appreciate that the resonance frequency infers the maximum related transfer in the system and that therefore given an input a maximum output is obtained.
For this particular case, the smaller the capacitance and inductance values, the higher the frequency obtained is likely to be.
Answer: When the electric field due to one is a maximum, the electric field due to the other is also a maximum, and this relation is maintained as time passes. They alternatively reinforce and cancel each other.
Explanation:
In a wave, the phase, is an arbitrary time reference, used to locate a given point of the wave in time, within a cycle.
Two waves can travel at the same speed, or even have the same wavelength, but this is not enough to be sure that at a given point in time, both waves will be in their maximum, as it only can be determined from the phase of the waves.
So, only when the waves reach at the same point in time at the same amplitude, we can say that they arrive in phase, in a constructive interference.