Answer: First option
Explanation: The higher the frequency, the higher the energy.
λν=c where λ is the wavelength, ν is the frequency and c is the speed of light. So when wavelength decreases, v increases and so does energy.
An AM radio wave has a very long wavelength. It therefore has a very low frequency and low energy.
A light wave has a very short wavelength. It therefore has a high frequency and high energy.
Answer:
Ceiling fan
Explanation:
Ceiling fan is a perfect and typical example of electrical energy being converted to mechanical energy.
In most systems, energy is usually transformed from one form to another. Energy is not created neither is it destroyed. We know this by virtue of law of conservation of energy.
- The ceiling fan is powered by electrical energy from an outlet.
- The energy from the outlet is used to drive the blades of the fan and set them into motion.
- This is mechanical energy.
Answer:
75.5g
Explanation:
From the ionic equation, we can write
next we find the number of charge
Note Q=it
for i=8.5A, t=3.75 to secs 3.75*60*60=13500secs
hence
Since one faraday represent one mole of electron which equal 96500C
Hence the number of mole produced by 114750C is
114750/96500=1.2mol
The mass of copper produced is
Hence the amount of copper produced is 75.5g
Answer:
A) 89.39 J
B) 30.39J
C) 23.8 J
Explanation:
We are given;
F = 30.2N
m = 3.5 kg
μ_k = 0.646
d = 2.96m
ΔEth (Block) = 35.2J
A) Work done by the applied force on the block-floor system is given as;
W = F•d
Thus, W = 30.2 x 2.96 = 89.39 J
B) Total thermal energy dissipated by the whole system which includes the floor and the block is given as;
ΔEth = μ_k•mgd
Thus, ΔEth = 0.646 x 3.5 x 9.8 x 2.96 = 65.59J
Now, we are given the thermal energy of the block which is ΔEth (Block) = 35.2J.
Thus,
ΔEth = ΔEth (Block) + ΔEth (floor)
Thus,
ΔEth (floor) = ΔEth - ΔEth (Block)
ΔEth (floor) = 65.59J - 35.2J = 30.39J
C) The total work done is considered as the sum of the thermal energy dissipated as heat and the kinetic energy of the block. Thus;
W = K + ΔEth
Therefore;
K = W - ΔEth
K = 89.39 - 65.59 = 23.8J
