Which phrase describes speed?

Arock is dropped from a cliff and reaches the ground in 2.70s. at the same time another rock is thrown horizontally from the same height with initial x velocity of 0.95 m/s. what distance will in x will the second rock cover?

What produces light and all other electromagnetic waves? a) the photoelectric phenomena b) heated metals c) charged particles d) radioactive samples (pls explain if you can : )

If an inclined plane is 5 m long and 2 m high, what is its mechanical advantage? a. 2.5 b. 3 c. 7 d. 10