Answer:
when the radius is halved, F becomes 4 times
Explanation:
<u><em>The formula is given by</em></u>

<u><em>When r is halved:</em></u>

=> 
=> 
<u><em>This means when the radius is halved, F becomes 4 times</em></u>
The wavelength of the note is

. Since the speed of the wave is the speed of sound,

, the frequency of the note is

Then, we know that the frequency of a vibrating string is related to the tension T of the string and its length L by

where

is the linear mass density of our string.
Using the value of the tension, T=160 N, and the frequency we just found, we can calculate the length of the string, L:
Answer:

Explanation:
We have:
diameter of the wheel, 
weight of the wheel, 
mass of hanging object to the wheel, 
speed of the hanging mass after the descend, 
height of descend, 
(a)
moment of inertia of wheel about its central axis:




Answer:
μ = 0.385
Explanation:
Given that,
The mass of the student, m = 69 Kg
The horizontal force applied, F = 260 N
The normal force acting on the body, weight = mg = 69g N
= 676.2 N
The coefficient of friction acting on a body is equal to the force acting on the body to the normal force acting on the body due to gravitation.
The formula for coefficient of friction,
μ = F / N
Substituting the values in the above equation,
μ = 260 N / 676.2 N
= 0.385
Hence, the coefficient of friction, μ = 0.385
Explanation:
The energy of the system before the collision must equal the energy after the collision.
After the collision the bullet and the block have a total mass of 18.41 kg and they move at a speed of 8.8 m/s. The kinetic energy after the collision is

Before the collision only the bullet has kinetic energy.
So we can now determine the speed of the bullet using
