I'm not very good at science and this is for a quiz that I'm taking right now. Which is a characteristic of the part of the atom marked "A”?

It contains most of the mass.
It is negatively charged.
It is mostly empty space.
It is composed of electrons.

Atransverse wave is traveling on a string stretched along the horizontal x-axis. the equation for the vertical displacement y of the string is given by y = (1.8 x 10-3)cos[π(13x - 60t)], where all quantities are in si units. what is the maximum speed of a particle of the string

The motor m applies a time-varying force of f (200 t) n, where t is in seconds. box b with mass 200 kg starts from rest, and the coefficients of kinetic and static friction are 0.2 and us 0.3 the acceleration due to gravity is g 9.8 m/s2 b 300 a) find the time ' when the box starts to move. b) calculate the speed of the crate at 3 s c) calculate the power delivered by the motor at t 3 s

Organelles are 1. responsible for producing power for the cell 2. tiny structures in the cell that carry out the cell's activities 3. responsible for digestion in the cell 4. found outside of the membrane