A) 
The total energy of the system is equal to the maximum elastic potential energy, that is achieved when the displacement is equal to the amplitude (x=A):
(1)
where k is the spring constant.
The total energy, which is conserved, at any other point of the motion is the sum of elastic potential energy and kinetic energy:
(2)
where x is the displacement, m the mass, and v the speed.
We want to know the displacement x at which the elastic potential energy is 1/3 of the kinetic energy:

Using (2) we can rewrite this as

And using (1), we find

Substituting
into the last equation, we find the value of x:

B) 
In this case, the kinetic energy is 1/10 of the total energy:

Since we have

we can write

And so we find:

Given:
F_gravity = 10 N
F_tension = 25 N
Let's find the net centripetal force exterted on the ball.
Apply the formula:

From the given figure, the force acting towards the circular path will be positive, while the force which points directly away from the center is negative.
Hence, the tensional force is positive while the gravitational force is negative.
Thus, we have:

Therefore, the net centripetal force exterted on the ball is 15 N.
ANSWER:
15 N
Answer:
Explanation:
Let Torque due to friction be
F
Net torque
= 46 - F
Angular impulse = change in angular momentum
=( 46 - F ) x 17 = I X 580
When external torque is removed , only friction creates torque reducing its speed to zero in 120 s so
Angular impulse = change in angular momentum
F x 120 = I X 580
( 46 - F ) x 17 = F x 120
137 F = 46 x 17
F = 5.7 Nm
b )
Putting this value in first equation
5.7 x 120 = I x 580
I = 1.18 kg m²
Basically, when someone is resting in an accelerated vehicle without restraint from a seatbelt, the force of stopping the vehicle will be when inertia occurs, and that force of the vehicle coming to a stop will affect the passenger (without a seatbelt/restraint from another force or object) greatly by throwing them.
For example;
If I were to be riding in a vehicle (without a seatbelt) that's accelerating at 40 m/s^2 and it suddenly gets slammed on the breaks, I will be thrown forward from inside the vehicle.
I hope this helps!
Answer: option C.
Fabrics such as cotton and silk are synthetic polymers
Explanation:
Fabrics such as cotton and silk are synthetic polymers because cotton and silk are natural polymers meaning they are gotten from natural source. Cotton is gotten from cotton plants and it is composed of cellulose which is a carbohydrates.
Silk also is gotten from animals I.efrom insect fibre or the cocoons of the larvae of the mulberry silkworm which is a polymer.