Answer:
F=30N
a= 3m/s^2
m=?
F=ma
30=m(3)
30/3=m
m=10kg
The mass of the ball is 10kg
Answer:
The angular acceleration is 
Explanation:
From the question we are told that
The moment of inertia is 
The net torque is 
Generally the net torque is mathematically represented as
Where 
is the angular acceleration so
substituting values
Answer:
K = -½U
Explanation:
From Newton's law of gravitation, the formula for gravitational potential energy is;
U = -GMm/R
Where,
G is gravitational constant
M and m are the two masses exerting the forces
R is the distance between the two objects
Now, in the question, we are given that kinetic energy is;
K = GMm/2R
Re-rranging, we have;
K = ½(GMm/R)
Comparing the equation of kinetic energy to that of potential energy, we can derive that gravitational kinetic energy can be expressed in terms of potential energy as;
K = -½U
