Answer: object B is negatively charged, object C is positively charged and object D is also positively charged
Explanation: since unlike charges attract and like charges repel, for object A which is positively charged and B to attract B must be negatively charged and then for B which is negatively charged and C to attract C must be positively charged and for C and D to repel they have to be of thesame charge which means D is positive as well.
Answer:
Explanation:
When we apply a horizontal force of 76 N to a block, the block moves across the floor at a constant speed. So net force on the block is zero .
It implies that a force ( frictional ) acts on it which is equal to 76 N in opposite direction ( friction )
When we apply a greater force on it it starts moving with acceleration .
This time kinetic friction acts on it due to rough ground equal to 76 N .This is limiting friction ( maximum friction )
Net force on the body in later case
= 89 - 76
= 13 N
Force by ground on the block in horizontal direction = 76 N ( FRICTIONAL FORCE )
=
Explanation:
The frequency of radio waves is 1.667 GHz
One portion of the same wave front travels 1.260 mm farther than the other before the two signals are combined.
There are two conditions for interference either constructive or destructive.
For constructive interference , the path difference is n times of wavelength and for destructive interference, the path difference is (n+1/2) times of wavelength
We can find wavelength in this case as follows :

If we divide path difference by wavelength,

It means that the path difference is 7 times of the wavelength. it means the two waves combine constructively and the value of m for the path difference between the two signals is 7.
If an experiment is conducted such that an applied force is exerted on an object, a student could use the graph to determine the net work done on the object.
The graph of the net force exerted on the object as a function of the object’s distance traveled is attached below.
- A student could use the graph to determine the net work done on the object by Calculating the area bound by the line of best fit and the horizontal axis from 0m to 5m
For more information on work done, visit
brainly.com/subject/physics