The weight is the force experienced, whereas the mass represents the actual quantity of matter inside a body..
weigh on the surface of the earth is equal to mg
mass is m
and at the centre weight is 0 due to 0 acceleration that's 0 g
but mass is always constant and remains m, no matter where you are
Answer:
0.776 m far Pinhole should be placed before the viewing screen
Explanation:
For circular aperture of diameter D will have a bright central maximum of diameter, width is given by

where
is wavelength of helium neon laser = 633 nm, D=10.cm, w=0.12 mm
Pinhole should be placed before the viewing screen is

Exert force upward.
Like when you pick something up from the floor, or walk up the stairs.
Energy is transfered when its moved from one object to another. The rate of energy transfered is called power. Work is the transfer of energy from one object to another.