Answer:
Yes, since the choice of the zero o potential energy is arbitrary.
Explanation:
The kinetic energy is due to the motion of the object. The expression for the kinetic energy is as follows;
Here, m is the mass of the object and v is the velocity of the object.
The kinetic energy can not be negative as the velocity is squared. It can be zero and positive.
Potential energy: It is the energy is due to the position of the object.
The expression for the potential energy is as follows;
PE= mgh
Here, g is the acceleration due to gravity and height.
Height can be taken from the reference point, zero which can be taken below zero and above zero. Zero is taken as origin. Below zero, the height is taken as negative and above zero, the height is taken as positive.
The potential energy can be zero, positive and negative.
The total energy is the sum of kinetic energy and potential energy.
E= KE + PE
Here, KE is the kinetic energy and PE is the potential energy.
Therefore, the option (B) is correct.
Answer:
- the coating’s index of refraction is 1.25
- the required thickness is 104.1667 nm
Explanation:
Given the data in the question;
Thickness of coating t = 100 nm
wavelength λ = 500nm
we know that refractive index is;
t = λ/4n
make n, the subject of formula
t4n = λ
n = λ / 4t
we substitute
n = 500 / ( 4 × 100 )
n = 500 / 400
n = 1.25
Therefore, the coating’s index of refraction is 1.25
2)
given that;
Index of refraction of the coating; n = 1.20
λ = 500 nm
thickness of coating t = ?
t = λ / 4n
we substitute
t = 500 / ( 4 × 1.2 )
t = 500 / 4.8
t = 104.1667 nm
Therefore, the required thickness is 104.1667 nm
Answer: Hazmat products are allowed in your FC are:
- A GPS unit (lithium batteries)
- A subwoofer (magnetized materials)
Explanation:
Hazmat products consist of flammable, corrosive and harmful substances which are actually very hazardous to human health and environment.
Hazardous material allowed in FC are as follows.
- Magnetized material products like as speakers.
- Non-spillable battery products like toy cars.
- Lithium-ion battery containing products like laptops, mobile phones etc.
- Non-flammable aerosol.
So, hazmat allowed products are GPS unit (lithium batteries) and subwoofer (magnetized materials).
Thus, we can conclude that hazmat products are allowed in your FC are:
- A GPS unit (lithium batteries)
- A subwoofer (magnetized materials)
<span>C. Does eating less fat increase a mouse's lifespan?
(If a mouse eats less fat in its meals then will it live longer: compared to other mice lives.
</span>This is a testable question that can be answered by designing and conducting an experiment.
I think D could be correct as well.
My final answer is D.
Answer:
Explanation:
The acceleration of gravity is 9.8m/s^2.
So to calculate the time it will take to make the ball stop(which btw means the ball now reach its greatest height), use the formula V1=V0+at. V1 is the final velocity(which is 0), V0 is the starting velocity(which is 30m/s), and the a(cceleration) is 9.8m/s^2.
(You can ignore the fact "at" is -30 instead 30, it's because the directions two velocity travel are opposite. )
We can now know the time it takes to make the ball stop just by the gravitational force is about 3 sec.
Use another formula S=1/2at^2, to find out the S(height) is 1/2*9.8*3^2=44.1, which is approximately D.45m .
