Answer:
Essentials. A battery is a device that stores chemical energy and converts it to electrical energy. The chemical reactions in a battery involve the flow of electrons from one material (electrode) to another, through an external circuit. The flow of electrons provides an electric current that can be used to do work.
A pair of equal gravitational forces ... one in each direction ...
exists between every speck of mass in the universe and every
other speck of mass.
Answer:
Image distance of apple=-6.7 cm
Magnification of apple=0.33
Explanation:
We are given that an apple is placed 20.cm in front of a diverging lens.
Object distance=u=-20 cm
Focal length=f=-10 cm
Because focal length of diverging lens is negative.
We have to find the image distance and magnification of the apple.
Lens formula

Substitute the values then we get




Image distance of apple=-6.7 cm
Magnification=m=
Magnification of apple=
Hence, the magnification of apple=0.33
Answer:

Explanation:
The torque of a force is given by:

where
F is the magnitude of the force
d is the distance between the point of application of the force and the centre of rotation of the system
is the angle between the direction of the force and d
In this problem, we have:
, the force
, the distance of application of the force from the centre (0,0)
, the angle between the direction of the force and a
Therefore, the torque is

repeated mesurement can reduce the error
it is true
if you take any mesurement repeatedly and the average is taken, the error will be less