I think the answer is Dust. Moons and stars definitely don't seem likely and dark particles, I am not even sure what those are. But I have seen rings on other planets before. Hope this helps. :)
Answer: 
Explanation:
Given
mass of laptop m=2 kg
The velocity of car u=8 m/s
The coefficient of static friction is 
The coefficient of kinetic friction is 
As the car is moving, so the coefficient of kinetic friction comes into play
deceleration offered by friction 
Using the equation of motion 
insert the values

Answer: Chemical → Mechanical → Electrical → Radiant
Explanation:
First, the Hamster eats the carrot, then the hamster is getting chemical energy.
Now the hamster starts using his wheel, then he "transforms" the chemical energy into mechanical energy.
Now the mechanical energy is connected to a generator, this means that the mechanical energy (the rotation of the wheel) is being converted into electrical energy.
And we know that there is a light bulb powered by this electrical energy, then we have electrical energy being transformed into radiant energy.
Then the correct option is:
Chemical → Mechanical → Electrical → Radiant
Answer:
He will complete the race in total time of T = 10 s
Explanation:
Total distance moved by the sprinter in 2.14 s is given as



now the distance remaining to move

now he will move with uniform maximum speed for the remaining distance
so we will have


so the total time to complete the race is given as
