Pretty sure it's 10 feet of plant debris to form 1 foot of coal.
To obtain the vertical component of the velocity, it is necessary to multiply the velocity at this time by sin 45 degrees. Since the velocity is not given, it must be solved first by dividing the distance by the time. To show this:
Velocity = distance / time
Velocity = 30 m / 4s
Velocity = 7.5 m/s
Vertical velocity = 7.5 sin 45
Vertical velocity = 5.3 m/s
