Which clouds are often associated with thunder and lightning?

What is the measurement of how fast an object moves relative to a reference point?

What is the measure of how much matter is in an object and that can be measured using a balance? a. height b. volume c. weight d. mass

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.