Answer:
a)
b)
Explanation:
a) Let's use the constant velocity equation:

- v is the speed of the muon. 0.9*c
- c is the speed of light 3*10⁸ m/s


b) Here we need to use Lorentz factor because the speed of the muon is relativistic. Hence the time in the rest frame is the product of the Lorentz factor times the time in the inertial frame.


v is the speed of muon (0.9c)
Therefore the time in the rest frame will be:



No we use the value of Δt calculated in a)

I hope it helps you!
Answer:
9.36*10^11 m
Explanation
Orbital velocity v=√{(G*M)/R},
G = gravitational constant =6.67*10^-11 m³ kg⁻¹ s⁻²,
M = mass of the star
R =distance from the planet to the star.
v=ωR, with ω as the angular velocity and R the radius
ωR=√{(G*M)/R},
ω=2π/T,
T = orbital period of the planet
To get R we write the formula by making R the subject of the equation
(2π/T)*R=√{(G*M)/R}
{(2π/T)*R}²=[√{(G*M)/R}]²,
(4π²/T²)*R²=(G*M)/R,
(4π²/T²)*R³=G*M,
R³=(G*M*T²)/4π²,
R=∛{(G*M*T²)/4π²},
Substitute values
R=9.36*10^11 m
The situation given above can be answered through the concept of the First Law of thermodynamics which states that the change in internal energy is equal to the difference between the work done and the heat added to the system. The work done by the object is negative and the heat added is positive.
change in internal energy = -500J + 1400 J = 900 J