You drop 12 balls off of a platform that is an unknown distance above the ground and measure the time it takes for the ball to fall to the ground. how far above the ground is the platform? give a range for this answer that you can be 95% sure that the true distance lies within. assume that g = 9.80 m/s2. all times are given in seconds.

Which statement is true if the refractive index of medium a is greater than that of medium b? a. total internal reflection is possible when light travels from air to medium b to medium a. b. total internal reflection is possible when light travels from medium a to medium b. c. total internal reflection is possible when light travels from medium b to medium a. d. total internal reflection is possible when light travels from air to medium a. e. total internal reflection is possible when light travels from air to medium b.

In addition to gravity, what is the other predominant force that affects the motion of a pendulum?

Estimate of the number of stars in our galaxy