Answer:

Explanation:
Given
-- initial velocity
--- height
Required
Determine the time to hit the ground
This will be solved using the following motion equation.

Where

So, we have:


Subtract 30.2 from both sides





Solve using quadratic formula:

Where




Split the expression
or 
or 
Time can't be negative; So, we have:


Hence, the time to hit the ground is 1.82 seconds
Answer:
When air resistance equals the weight of an object, the object has reached free fall.
Explanation:
- When an object has only force acting on it as gravity then, it experiences free fall.
- During free fall all the forces except gravity is balanced by one another.
- In the question, object's weight is balanced by air resistance so it is in the state of free fall.
- At the null point of free fall, object experiences weightlessness i.e. it feels like object is not attracted by any force.
Answer:
(D) energy from one place to another
Wavespeed = frequency x wavelength
= 14 x 9
= 126 mm/s
= 0.126 m/s
True
~Nightcore
Hope this helped