A)
The total energy of the system is equal to the maximum elastic potential energy, that is achieved when the displacement is equal to the amplitude (x=A):
(1)
where k is the spring constant.
The total energy, which is conserved, at any other point of the motion is the sum of elastic potential energy and kinetic energy:
(2)
where x is the displacement, m the mass, and v the speed.
We want to know the displacement x at which the elastic potential energy is 1/3 of the kinetic energy:
Using (2) we can rewrite this as
And using (1), we find
Substituting into the last equation, we find the value of x:
B)
In this case, the kinetic energy is 1/10 of the total energy:
Since we have
we can write
And so we find:
<span>Frequency x Wavelength = Speed of light
Now, speed of light = 3 x 10^5 km/s = 3 x 10^8 m/s = 3 x 10^10 cm/s
Frequency = speed/Wavelength
= (3 x 10^10)/(4.257 x 10^-7)
=7 x 10^16 Hz</span>
Answer:
The percentage power lost in the transmission line if the voltage not stepped up is 50%.
Explanation:
Given that,
Current = 60 A
Voltage = 120 V
Resistance = 1.0 ohm
We need to calculate the power
Using formula of power
Where,I =current
V = voltage
Put the value into the formula
We need to calculate the percentage power lost in the transmission line
If the voltage is not stepped up
Then, the power loss
Put the value into the formula
The percentage power loss P''
Hence, The percentage power lost in the transmission line if the voltage not stepped up is 50%.
A chemical property of gasoline is that it will burn in air. Gasoline is a substance that is used to power automobiles. Gasoline will oxidize
in air which means that it reacts with oxygen in air. Hope this answers the question. Have a nice day.
Answer:
78 km/h
Explanation:
If I normally drive a 12 hour trip at an average speed of 100 km/h, my destination has a total distance of:
- 100 km/h · 12 h = 1,200 km
Today, I drive the first 2/3 of the distance at 116 km/h. Let's first calculate what 2/3 of the normal distance is.
I've driven 800 km already. I need to drive 400 km more to reach my final destination. I need to figure out my average speed during this last 1/3 of the distance.
To do this, I first need to calculate how much time I spent driving 116 km/h for the past 800 km.
- 116 km/1 h = 800 km/? h
- 800 = 116 · ?
- ? = 800/116
- ? = 6.89655172
I spent 6.89655172 hours driving during the first 2/3 of the distance.
Now, I need to subtract this value from 12 hours to find the remaining time I have left.
- 12 h - 6.89655172 h = 5.10344828 h
Using this remaining time and my remaining distance, I can calculate my average speed.
- ? km/1 hr = 400 km/5.10344828 h
- 5.10344828 · ? = 400
- ? = 400/5.10344828
- ? = 78.3783783148
My average speed during the last third of the distance is around 78 km/h.