<u>Answer</u>
Fossils are remains from animals and plants. They are embedded in rock and preserved in petrified form.
In a fossil fuels power plant carbon fuels such as oil, coal and gas are burnt to generate steam that are used to turn large turbines that generate electricity.
These turbines turn magnetic fields inside conductor inducing a large current in them.
Fossils fuels are much reliable as they can be used for a long period of time.
Answer:
f = 7.97 x 10⁶ Hz = 7.97 MHz
Explanation:
The speed of a wave is given by the following formula:

where,
v = speed of the ultrasound wave through human tissue = 1540 m/s
f = frequency of ultrasound wave required = ?
λ = wavelength of ultrasound waves = smallest detail required = 0.193 mm
λ = 0.193 mm = 1.93 x 10⁻⁴ m
Therefore,
<u>f = 7.97 x 10⁶ Hz = 7.97 MHz</u>
Answer:
work done will be equal to 305.05 J
Explanation:
We have given force exerted F = 45 N
Angle with the horizontal 
Distance moved due to exerted force d = 9.1 m
Work done is equal to
, here F is force
is angle with horizontal and d is distance moved due to force
So work done 
So work done will be equal to 305.05 J
The change in Potential energy of the cat is 176.4 J.
<h3 /><h3>Potential Energy:</h3>
This is the energy due to the position of a body. The S.I unit is Joules (J)
The formula for change in potential energy.
<h3 /><h3>Formula:</h3>
- ΔP.E = mg(H-h).............. Equation 1
<h3>Where:</h3>
- ΔP.E = Change in potential energy
- m = mass of the cat
- g = acceleration due to gravity
- H = First height
- h = second height.
From the question,
<h3>Given:</h3>
- m = 15 kg
- H = 2.5 m
- h = 1.3 m
- g = 9.8 m/s²
Substitute these values into equation 1
- ΔP.E = 15×9.8(2.5-1.3)
- ΔP.E = 15×9.8×1.2
- ΔP.E = 176.4 J.
Hence, The change in Potential energy of the cat is 176.4 J
Learn more about Potential energy here: brainly.com/question/1242059