Gravity is a force between any two objects with mass. why doesn't a person feel a gravitational force between him/herself and another person?
a) a person doesn't exert a gravitational force.
b) the two gravitational forces cancel each other out.
c) the gravitational forces of people is so small it is
overshadowed by that of earth.
d) there are so many people we are actually balanced by all the different gravitational forces.

Avertical clean glass piezometer tube has an inside diameter of d = 1 mm and is used to measure pressure in a horizontal pipe carrying water as shown. due to pressure in the pipe, the water at 20c rises into the tube to a height h. if the water pressure in the pipe is p = 500 pa gauge, estimate the height h: (a) without considering surface tension (b) with surface tension (capillary) effects. the contact angle  can be assumed at 30 deg

How many electrons in an atom could have these sets of quantum numbers? =3n=3 electronselectrons =4,ℓ=2n=4,ℓ=2 electronselectrons =6,ℓ=ℓ=−1n=6,ℓ=2,mℓ=−1

Awave is propagating from left to right in a medium. the particles in the medium are also vibrating from left to right. what kind of wave does this describe? a. longitudinal wave b. transverse wave c. mechanical wave d. electromagnetic wave