For physics, I would recommend to just keep doing practice problems and reviewing notes. Repetition of the same concepts will help drill it into your brain. Hope that helps!
Answer:
Magnets are employed to generate electricity.
Explanation:
Magnets' characteristics are employed to generate electricity. Electrons are pulled and pushed by moving magnetic fields. When you move a magnet around a coil of wire, or a coil of wire around a magnet, the electrons in the wire are pushed out and an electrical current is created.
Answer:
e*P_s = 11 W
Explanation:
Given:
- e*P = 1.0 KW
- r_s = 9.5*r_e
- e is the efficiency of the panels
Find:
What power would the solar cell produce if the spacecraft were in orbit around Saturn
Solution:
- We use the relation between the intensity I and distance of light:
I_1 / I_2 = ( r_2 / r_1 ) ^2
- The intensity of sun light at Saturn's orbit can be expressed as:
I_s = I_e * ( r_e / r_s ) ^2
I_s = ( 1.0 KW / e*a) * ( 1 / 9.5 )^2
I_s = 11 W / e*a
- We know that P = I*a, hence we have:
P_s = I_s*a
P_s = 11 W / e
Hence, e*P_s = 11 W
Answer: The coefficient of kinetic friction is μ = 0.6
Explanation:
For an object of mass M, the weight is:
W = M*g
where g is the gravitational acceleration: g = 9.8m/s^2
And the friction force between this object and the surface can be written as:
F = W*μ
where μ is the coefficient of friction (kinetic if the object is moving, and static if the object is not moving, usually the static coefficient is larger)
In this case, the weight is:
W = 20N
And the friction force is:
F = 12N
Replacing these values in the equation for the friction force we get:
12N = 20N*μ
(12N/20N) = μ = 0.6
The coefficient of kinetic friction is μ = 0.6
