Here I advice doing thought experiment and not remembering equations. By doing thought experiment you will write down equation by yourself.
Doing some work on a system means that system will "absorb" that energy. Here, system absorbs 1000J of energy. Now you are cooling system down by removing 500J of energy. That means that system will lose 500J of energy
All of that can be written as 1000 - 500 = 500 which means that after cooling your system has 500J left.
Answer:
?
Explanation:
Im confused what do you mean?
Answer:
1) A time-varying magnetic field will produce an electric field.
4) A time-varying electric field will produce a magnetic field.
Explanation:
1) A time-varying magnetic field will produce an electric field.
TRUE
time varying magnetic field will produce electric field which is given as
![E = \frac{r}{2}\frac{dB}{dt}](https://tex.z-dn.net/?f=E%20%3D%20%5Cfrac%7Br%7D%7B2%7D%5Cfrac%7BdB%7D%7Bdt%7D)
2) Time-varying electric and magnetic fields can propagate through space only if there is no matter in their path.
FALSE
Time varying electric field and magnetic field will induce each other and it can travel through any medium as well as it can travel without any medium also
3) Electric and magnetic fields can be treated independently only if they vary in time.
FALSE
electric field can be due to stationary charge and magnetic field due to current carrying elements so it is not compulsory to have time varying
4) A time-varying electric field will produce a magnetic field.
TRUE
Time varying electric field will produce magnetic field given as
![B = \frac{\mu_o\epsilon_o A}{2r}\frac{dE}{dt}](https://tex.z-dn.net/?f=B%20%3D%20%5Cfrac%7B%5Cmu_o%5Cepsilon_o%20A%7D%7B2r%7D%5Cfrac%7BdE%7D%7Bdt%7D)
Answer: A) soft.
Explanation:
Nylon is a big covalent molecule as it formed by polymerization of small units called as monomers. It is a synthetic polymer and is prepared in labs.
Nylon polymers are soft, light in weight, have high melting point, have excellent resistance towards abrasion and are very resistant to heat.
Thus Nylon is used in making backpacks as it is soft.
Answer:
(a) Magnitude of static friction force is 109 N
(b) Minimum possible value of static friction is 0.356
Solution:
As per the question;
Horizontal force exerted by the girl, F = 109 N
Mass of the crate, m = 31.2 kg
Now,
(a) To calculate the magnitude of static friction force:
Since, the crate is at rest, the forces on the crate are balanced and thus the horizontal force is equal to the frictional force, f:
F = f = 109 N
(b) The maximum possible force of friction between the floor and the crate is given by:
![f_{m} = \mu_{s}N](https://tex.z-dn.net/?f=f_%7Bm%7D%20%3D%20%5Cmu_%7Bs%7DN)
where
N = Normal reaction = mg
Thus
![f_{m} = \mu_{s}mg](https://tex.z-dn.net/?f=f_%7Bm%7D%20%3D%20%5Cmu_%7Bs%7Dmg)
For the crate to remain at rest, The force exerted on the crate must be less than or equal to the maximum force of friction.
![f\leq f_{m}](https://tex.z-dn.net/?f=f%5Cleq%20f_%7Bm%7D)
![f \leq \mu_{s}mg](https://tex.z-dn.net/?f=f%20%5Cleq%20%5Cmu_%7Bs%7Dmg)
![109 \leq \mu_{s}\times 31.2\times 9.8](https://tex.z-dn.net/?f=109%20%5Cleq%20%5Cmu_%7Bs%7D%5Ctimes%2031.2%5Ctimes%209.8)
![\mu_{s}\geq 0.356](https://tex.z-dn.net/?f=%5Cmu_%7Bs%7D%5Cgeq%200.356)