Students in Dr. Branch's physics class were calculating the average time required for one complete period of a pendulum bob. They set up five pendulums and timed the swing for each one twenty-five times. Then they calculated the average period time One set of data varied significantly from the other sets. What could be one source of unavoidable error that influenced the data?

A) reading the stop watch incorrectly

B) stop watch starts with one second on the clock

C) not starting the timer at exactly the “go” call

D) students not paying attention to data collection

What happens in a global convection cell

An electron moves with a constant horizontal velocity of 3.0 × 106 m/s and no initial vertical velocity as it enters a deflector inside a tv tube. the electron strikes the screen after traveling 26 cm horizontally and 19 cm vertically upward with no horizontal acceleration. what is the constant vertical acceleration provided by the deflector? (the effects of gravity can be ignored.)

Aball is thrown from the top of a building with an initial velocity of 21.9 m/s straight upward, at an initial height of 51.6 m above the ground. the ball just misses the edge of the roof on its way down, as shown in the figure. (a) determine the time needed for the ball to reach its maximum height. (b) determine the maximum height. (c) determine the time needed for the ball to return to the height from which it was thrown, and the velocity of the ball at that instant. (d) determine the time needed for the ball to reach the ground. (e) determine the velocity and position of the ball at t = 5.35 s.