Answer:
v_{f2} = √ 2 v_{f}
Explanation:
Work and kinetic energy are related by
W = ΔK
The formula for work is
W = F . d
The formula for kinetic energy is
K = ½ m v²
W = - K₀
Since the body starts from rest, the initial velocity is ro and therefore the kinetic energy is zero.
W = K_{f}
W = ½ m v_{f}²
v_{f} = √ 2W / m
If W = 2 W₀
v_{f2} = √ 2 (2W₀) / m
v_{f2} = √ 2 √2W₀ / m
v_{f2} = √ 2 v_{f}
Answer:
The observed wavelength on Earth from that hydrogen atom is .
Explanation:
Given that,
The actual wavelength of the hydrogen atom,
A hydrogen atom in a galaxy moving with a speed of,
We need to find the observed wavelength on Earth from that hydrogen atom. The speed of galaxy is given by :
is the observed wavelength
So, the observed wavelength on Earth from that hydrogen atom is . Hence, this is the required solution.
I think that they scored higher becuase there brain wasnt full of random everydy thoughts during the test. There brain had more room for the test and wasnt distracted
The correct option is
<span>D) can be transformed to different voltages
In fact, transformers can be used in order to change the voltage of an alternating current. This feature is particularly useful, because it allows to transmit electricity through power lines using very high voltages, and this allows to reduce the power dissipated along the lines.
In fact, the power generated by a power station is the product between the current and the voltage:
</span>
<span>So the current is:
</span>
(1)
<span>
The power dissipated along the transmission line, instead, is given by
</span>
<span>and if we use (1) inside this, we find
</span>
<span>so we see that the higher the voltage, the lower the power dissipated along the transmission lines.
Then, transformers are also used at the end of the power lines, in order to convert these very high voltages into the standard voltage (e.g. 240 V) used by household appliances.</span>
Answer:
Solids have a definite shape and volume, its particles vibrate slowly.
Liquids have no definite shape, the particles move randomly around its container, and they have a fixed volume.