Assume the motion when you are in the car or in the school bus to go to the school.
To describe the motion the first thing you need is a point of reference. Assume this is your house.
This should be a description:
- When you are sitting and the car has not started to move you are at rest.
- The car starts moving from rest, gaining speed, accelerating. You start to move away from your house, with a positive velocity (from you house to your school) and positive acceleration (velocity increases).
- The car reaches a limit speed of 40mph, and then moves at constant speed. The motion is uniform, the velocity is constant, positive, since you move in the same direction), and the acceleration is zero.
- When the car approaches the school, the driver starts to slow down. Then, you speed is lower but yet the velocity is positive, as you are going in the same direction. The acceleration is negative because it is in the opposite direction of the motion.
- When the car stops, you are again at rest: zero velocity and zero acceleration.
- In all the path your velocity was positive, constant at times (zero acceleration) and variable at others (accelerating or decelerating).
- When you comeback home, then you can start to compute negative velocities, as you will be decreasing the distance from your point of reference (your house).
Answer:
Explanation:
Area of the loop = a b
current = I
magnetic moment of the loop M = area x current
= ab I
Torque on the loop = MB sinθ
here θ = 90
Torque = MB
= abIB
In this case net force on the loop will be zero because here torque is created by two equal and opposite force acting on two opposite sides of the loop so net force will be zero .
A more in depth description:
as gasses like hydrogen start to gather, it creates more mass, therefore more gravitational attraction. As the gasses start to collect to considerably large amounts, the gas at the center of the mass starts to compress. As the gas keeps growing, the immense pressure on the core grows and grows, raising the temperature to extreme amounts. As this happens the star starts to undergo a process called nuclear fusion. this process occurs when immense pressure and heat cause the electrons to escape from their nuclei and flow around freely. this is what the fourth state of matter is. this type of matter is called plasma. this alone creates incredible amounts of heat and energy. The main part of the fusion process though is that the nuclei in which the electrons escaped from begin to merge, creating heavier nuclei, therefore creating heavier and denser nuclei. as the nuclei combine they also form denser elements, such as helium (fist merge of nuclei) all the way to eventually iron (last merge before nuclei is at its heaviest. This entire process takes billions of years to go from helium to the extremely dense iron, and stars usually only reach iron if they are big enough (a lot larger than our sun) so that the pressure will be able to keep fusing nuclei. if they dont reach iron, at the end of their life, the fuel from the inside will be used up and the core has to compensate for the gravitational force of the outer star pushing in. this means the star will grow as the outward force becomes greater than the gravitational force. the star will stay like this for a while before finally using up all the fuel and slowly dying off and shrinking. the shrinking star (or dying star) is known as a white dwarf
that is the long answer