Answer:
it's C
Explanation:
have a nice day............
Answer:
h=12.41m
Explanation:
N=392
r=0.6m
w=24 rad/s

So the weight of the wheel is the force N divide on the gravity and also can find momentum of inertia to determine the kinetic energy at motion


moment of inertia

Kinetic energy of the rotation motion

Kinetic energy translational

Total kinetic energy

Now the work done by the friction is acting at the motion so the kinetic energy and the work of motion give the potential work so there we can find height

Answer:
s=800 m
Explanation:
Given that,
Acceleration of a runner, a = 4 m/s²
Time, t = 20 seconds
We need to find the distance covered by her. Initially, she was at rest. It means its initial velocity is equal to 0. So, using second equation of motion as follows :

Herre, u = 0

So, she will cover a distance of 800 m.
Answer:
The electron’s velocity is 0.9999 c m/s.
Explanation:
Given that,
Rest mass energy of muon = 105.7 MeV
We know the rest mass of electron = 0.511 Mev
We need to calculate the value of γ
Using formula of energy


Put the value into the formula


We need to calculate the electron’s velocity
Using formula of velocity




Put the value into the formula



Hence, The electron’s velocity is 0.9999 c m/s.
Answer: An 8 kg book at a height of 3 m has the most gravitational potential energy.
Explanation:
Gravitational potential energy is the product of mass of object, height of object and gravitational field.
So, formula to calculate gravitational potential energy is as follows.
U = mgh
where,
m = mass of object
g = gravitational field = 
h = height of object
(A) m = 5 kg and h = 2m
Therefore, its gravitational potential energy is calculated as follows.

(B) m = 8 kg and h = 2 m
Therefore, its gravitational potential energy is calculated as follows.

(C) m = 8 kg and h = 3 m
Therefore, its gravitational potential energy is calculated as follows.

(D) m = 5 kg and h = 3 m
Therefore, its gravitational potential energy is calculated as follows.

Thus, we can conclude that an 8 kg book at a height of 3 m has the most gravitational potential energy.