An electroscope is a device that detects charge on objects that touch it or are brought near it. john rubs a piece of cotton fabric on a plastic rod and then touches the rod to the electroscope.
what methods of charging does john use?
the speed of the box will decrease and the box will slow down.
initially the box with some mass is moving with some speed. hence we can say the box has some momentum. the momentum of the box must remain constant. as the box gains water due to downpour of rainfall, the mass of the box or system increases . momentum which is product of mass and velocity has to remain constant. to remains constant , as the mass increase the speed decrease so as to keep the product constant.
when the compass placed near the working of electric wire, the compass needle will be redirected towards the magnetic field created by wire.
the electric wire cause the magnetic field just like a magnet causes magnetic field.
the electric currents always produces their magnetic fields. when we put the compass near the electric wire the current passes through it, and the needle of the compass will not move in north or south, instead, the needle will be pointed in the direction of magnetic field created by the wire.
3 is b my dude and the reason nobody answered is because thousands of questions are asked every day. so not every question can be answered. it doesn't have to do with being lazy.
as we know that work done is defined as product of force and displacement
so here we will have
so here we know that
also we know that
now we will have
so it will have 27500 n force on it