To solve this problem it is necessary to apply the kinematic equations of angular motion.
Torque from the rotational movement is defined as
where
I = Moment of inertia 
For a disk
Angular acceleration
The angular acceleration at the same time can be defined as function of angular velocity and angular displacement (Without considering time) through the expression:
Where
Final and Initial Angular velocity
Angular acceleration
Angular displacement
Our values are given as
Using the expression of angular acceleration we can find the to then find the torque, that is,
With the expression of the acceleration found it is now necessary to replace it on the torque equation and the respective moment of inertia for the disk, so
Therefore the torque exerted on it is 
Answer:
Because heat is a path function or the energy in transit.
Explanation:
- It is not correct to say that a body contains a certain amount of heat because the heat is a path function and not a property of the system. It is the energy in transit which can be encountered only when it crosses the system boundary.
- Heat is the energy in transit of a matter which flows by the virtue of temperature difference. The heat energy in a body is stored in the form of kinetic energy of the molecules which gets converted into heat that we know as the responsible factor for the rise in temperature usually.
The correct matching are the following:
- A. magnetic field: prevents charged particles from the sun from reaching the surface
- B. ozone: filters cancer-causing rays from the sun
- C. carbon dioxide: retains heat energy from the sun in the atmosphere
- D. water in oceans, lakes, rivers and streams: moderates changes in temperature on the surface
The electromagnetic field of the Earth protects us from solar wind by deflecting it. Without it, the charged particles would strip away our ozone, which will lead to the end of life on Earth.
The ozone is a layer in the stratosphere that filters the suns rays. It filters the UV rays by absorbing it. This prevents the UV rays from damaging the surface of the Earth.
Carbon dioxide retains heat in the atmosphere, which creates a greenhouse effect. It is beneficial for us, but because human activity like industrial activities emit so much carbon in the atmosphere that it ends up being harmful.
Bodies of water found on Earth regulate the temperature of the Earth through ocean currents. It brings in both cold and warm air to land which also affect precipitation.
Long explanation, I know, but maybe this will help you out in the long run. Good Luck!
Answer:
a) 4.2m/s
b) 5.0m/s
Explanation:
This problem is solved using the principle of conservation of linear momentum which states that in a closed system of colliding bodies, the sum of the total momenta before collision is equal to the sum of the total momenta after collision.
The problem is also an illustration of elastic collision where there is no loss in kinetic energy.
Equation (1) is a mathematical representation of the the principle of conservation of linear momentum for two colliding bodies of masses 
and 
whose respective velocities before collision are 
and 
;
where 
and 
are their respective velocities after collision.
Given;
Note that =0 because the second mass was at rest before the collision.
Also, since the two masses are equal, we can say that 
so that equation (1) is reduced as follows;
m cancels out of both sides of equation (2), and we obtain the following;
a) When 
, we obtain the following by equation(3)
b) As stops moving 
, therefore,
Newton's third law states that for every action, there is an equal and opposite reaction. When you let go of the ballon, you are letting the force out but the force also pushes the balloon back.
