Answer:
we can say that with a smaller magnitude , the field will point is in same direction
Explanation:
we have given that
solenoid is filled with a diamagnetic material and with air, magnetic field pointing along its axis in the positive x direction
so in small magnitude, the field will point is in same direction
Answer:
The total mechanical energy does not change if the value of the mass is changed. That is, remain the same
Explanation:
The total mechanical energy of a spring-mass system is equal to the elastic potential energy where the object is at the amplitude of the motion. That is:
(1)
k: spring constant
A: amplitude of the motion = 2.0cm
As you can notice in the equation (1), the total mechanical energy of the system does not depend of the mass of the object. It only depends of the amplitude A and the spring constant.
Hence, if you use a mass of 0.40kg the total mechanical energy is the same as the obtained with a mas 0.20kg
Remain the same
Answer:
Explanation:
As the disc is unrolling from the thread then at any moment of the time
We have force equation as
also by torque equation we can say
Now we have
Also from above equation the tension force in the string is
Factors affecting friction
The intensity of friction depends on following factors: i) The area involved in friction. ii) The pressure applied on the surfaces. Force = Pressure ´ Area Frictional force will increase, if the area of contact will increase or if pressure applied on the surface increased.
Methods to reduce friction
i) Polish the contact surface. ii) Put oil or grease so that it fills in the small gaps of the flat parts. iii) Use ball bearings to reduce area of contact between rotating parts.
Lubrication
Following methods can be used to reduce friction: Oil is either thin or viscous. It depends upon SAE No. of oil. (SAE means Society of Automotive Engineers). If we use very viscous oil, it does not reach all the parts. Very thin oil will flows away easily and gets wasted. Grease is used in such cases. It is generally used around ball-bearing. Normal grease or oil is never used where there is high pressure, high temperature and high speed. Special lubricants are used in such cases. In cold season the oil becomes thick and in hot season it becomes thin. Therefore selection of lubrication also depends on the season. It is always advisable to refer operating manual of the equipment before selecting the lubricant.
