Galileo sometimes used his pulse to time motions. what was the timing problem that galileo encountered? (drop a rubber ball from a height of about 2 m and try to determine how many pulse beats elapsed before it hits the ground.)

Contrast the force of gravity between these pairs of objects a 1 kg mass and a 2 kg mass that are 1 m apart and two 2 kg masses that are 1 m apart

When a vertical beam of light passes through a transparent medium, the rate at which its intensity i decreases is proportional to i(t), where t represents the thickness of the medium (in feet). in clear seawater, the intensity 3 feet below the surface is 25% of the initial intensity i0 of the incident beam. what is the intensity of the beam "10" feet below the surface? (give your answer in terms of i0. round any constants or coefficients to five decimal places.)

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2