Answer
a) For the rock






b)
for maximum range




c) The value of θ is the same on every planet as g divides out.
Not totally sure but i would say a normal? its not refraction or incidence if its perpendicular and i dont think its a mirror if its an imaginary line so yeah normal (normals are always perpendicular to their surface too i think so)
Answer:
Yes,in fact visible 'light' is a form of radiation, which can be defined as an energy that travels in the form of electromagnetic waves. It can also be described as a flow of particle-like 'wave-packets', called photons, that travel constantly at the speed of light (about 300 000 kilometres per second).
Explanation:
Complete Question
A 10 gauge copper wire carries a current of 20 A. Assuming one free electron per copper atom, calculate the drift velocity of the electrons. (The cross-sectional area of a 10-gauge wire is 5.261 mm2.)
mm/s
Answer:
The drift velocity is 
Explanation:
From the question we are told that
The current on the copper is 
The cross-sectional area is
The number of copper atom in the wire is mathematically evaluated

Where
is the density of copper with a value 
is the Avogadro's number with a value 
Z is the molar mass of copper with a value 
So
Given the 1 atom is equivalent to 1 free electron then the number of free electron is

The current through the wire is mathematically represented as

substituting values

=> 
Average speed = distance travelled / time used