What kind of energy does a skier have standing still at the top of a hill?
1 answer:
You might be interested in
Answer:
0.56
Explanation:
Let the coefficient of friction is μ.
m = 4.3 kg, θ = 30 degree, initial velocity, u = 0, s = 2.7 m, t = 5.8 s
By the free body diagram,
Normal reaction, N = mg Cosθ = 4.3 x 9.8 x Cos 30 = 36.49 N
Friction force, f = μ N = 36.49 μ
Net force acting on the block,
Fnet = mg Sinθ - f = 4.3 x 9.8 x Sin 30 - 36.49 μ
Fnet = 21.07 - 36.49μ
Net acceleartion, a = Fnet / m
a = (21.07 - 36.49μ) / 4.3
use second equation of motion
s = ut + 1/2 a t^2
2.7 = 0 + 1/2 x (21.07 - 36.49μ) x 5.8 x 5.8 / 4.3
By solving we get
μ = 0.56
Option (b) is correct. The certain materials can act as superconductors at a very low temperature.
Explanation:
The Superconductivity of a material is the property of the particular substance to provide no resistance to the path of the current through it. The current does not face any hindrance due to the motion of the other particles inside the conductor.
The superconductivity of a substance leads to the flow of current through the substance or the material without any hindrance. The resistance of a substance is due to the motion of the particles inside it. If all the motion occurring inside the substance are seized, there will be no resistance offered by the conductor.
Therefore, the superconductivity can be defined as the state where all the motions inside the a material are seized. This occurs at a very low temperature. The absolute zero temperature is regarded as the temperature where there is no motion in any particle.
Thus, Option (b) is correct. The certain materials can act as superconductors at a very low temperature.
Learn More:
1. An electrical shock happens when electric brainly.com/question/3059888
2. A capacitor with capacitance (c) = 4.50 μf is connected to a 12.0 v battery brainly.com/question/8892837
3. Reason for the difference in resistance of bulb brainly.com/question/10421964
Answer Details:
Grade: High School
Subject: Physics
Chapter: Conductivity
Keywords:
material, superconductor, motion, pressure, cold, temperature, substance, material, conditions, superconductivity.