One of the equations of gravity is this:

Where v = final velocity which is 7m/s
u = initial velocity which is 0 for objects falling from a height
g = acceleration due to gravity and it is approximately 10m/s^2. It's a constant so pretty much remember this number. It's positive since the work being done is caused by gravity (in other words, it's falling down). It can also be negative if the work being down is against gravity (in other words, it's going up)
h = height of object
Substitute for the values and you should have something like this



Answer:
A) object moves 20 N [West] or -20 N [East]
B) object moves 6 N [South] or -6 N [North]
C) object moves 90 N [West] or -90 N [East]
D) object does not move and is at rest*
*Rest means 0
Why:
A)both forces from north and south that are pushing against the object neutralize each other. Assume that north is positive and south is negative: 20 [N] + (-20) [S] = 0
On West and east, you can see that west has a greater force. Assume that west is negative and east is positive: 50 [E] + (-70) [W] = -20 [E]
Answer:
The 2 light bulbs can be connected in parallel to each other to avoid disconnection when one bulb burns out.
Explanation:
The parallel connection is required not series. A parallel connection is the connection of electronic components (e.g bulbs, LED, resistors, capacitors etc) in such a way that the same voltage is supplied across the ends of the components. While in a series connection, the components are connected to each other end-to-end.
As regard the question, parallel connection ensures that the brightness any of the bulbs is not affected with respect to the other bulbs. And other bulbs continue to function when any burns out. The 2 light bulbs should be connected in parallel to the baterry to avoid disconnection of all the bulbs.
The sound mixer will need to increase the amplitude of the sound wave produced by the singer which will increase the loudness of the sound.
<h3>Amplitude of sound wave</h3>
The amplitude of a sound wave is the maximum vertical displacement of the sound wave.
The sound mixer will need to increase the amplitude of the sound wave produced by the singer.
The increase in the amplitude of the sound wave produced by the lower tune singer will result in increased loudness of the sound.
Thus, the sound mixer will need to increase the amplitude of the sound wave produced by the singer which will increase the loudness of the sound.
Learn more about sound waves here: brainly.com/question/1199084
Ocean waves propagate through the medium called 'sea water'.