I can't see the answers clearly, but I can see the question. So, I'll just give you a clue/hint.
A stars brightness actually depends on how far it is from your location. If it's far away, it will be dimmer than its counterpart that is closer. To summarize it, if two stars have the same brightness level and one is farther away than the other, the one farther away will appear dimmer than its closer counterpart.
For number 2 the answer is a change in color.
Material b has highest heat
Answer:
- 9m/s²
Explanation:
Given parameters:
Initial velocity = 40m/s
Time taken = 3s
Final velocity = 13m/s
Unknown:
Acceleration of the car = ?
Solution:
Acceleration is the rate of change of velocity with time taken.
Acceleration = 
Acceleration = 
= - 9m/s²
Answer:
I = M*(0.5R^2 + h^2)
w = sqrt [2*g*h / (0.5R^2 + h^2)]
Explanation:
Given:
- The radius of the cylinder R
- The mass of the cylinder M
- The distance between horizontal axis h
- The moment of inertia of cylinder I_c
Solution:
- When the axis of rotation and axis with respect to rotation inertia is required do not coincide then we have to apply parallel axis theorem to calculate the moment of inertia about the required axis which is at a distance h from body rotational axis as follows:
I = I_c + M*h^2
- Where I_c of a cylinder is = 0.5*M*R^2
I = 0.5*M*R^2 + M*h^2
I = M*(0.5R^2 + h^2)
- From conservation of total mechanical energy of the cylinder, the change in gravitational potential energy ΔP.E plus the change in kinetic energy ΔK.E of the cylinder must be zero:
ΔP.E = ΔK.E
M*g*h = 0.5*I*w^2
M*g*h = 0.5*M*(0.5R^2 + h^2)*w^2
w^2 = 2*g*h / (0.5R^2 + h^2)
w = sqrt [2*g*h / (0.5R^2 + h^2)]
Where,
w: The angular speed of the cylinder
