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:
16.6 kJ/°C
Explanation:
given,
Amount of heat absorbed = 45 kJ
initial temperature, T₁ = 25.5°C
final temperature, T₂ = 28.2°C
change in temperature = T₂ - T₁
= 28.2 - 25.5 = 2.7° C



Heat capacity of the object is equal to 16.6 kJ/°C
Answer:
Number of electrons, 
Explanation:
Given that,
Charge on the fur, 
A piece of amber is charged by rubbing with a piece of fur. We need to find the electrons were added to the amber. It can be calculated using the quantization of charge as
q = n × e
Where
n is the number of electrons
e is the charge on electron

So,
number of electrons are added to the amber. Therefore, this is the required solution.
This question involves the use of the equations of motion for vertical motion.
The time taken by the stones P and Q to reach the ground is the same, that is "2 s".
The velocity with which Q hits the ground is "20 m/s".
The time taken by the stones to reach the ground can be calculated by using the second equation of motion for the vertical motion:

For both the stones P and Q:
h = height = 20 m
= initial velocity = 0 m/s
t = time = ?
g = acceleration due to gravity = 10 m/s²
Therefore,

<u>t = 2 s</u>
<u></u>
Hence, the time taken by both the stones to reach the ground <u>is the same</u>.
To find the final velocity of stone Q we will use the first equation of motion for the vertical motion:

Learn more about equations of motion here:
brainly.com/question/20594939?referrer=searchResults
The attached picture shows the equations of motion in the horizontal and vertical directions.