I thought you were going to ask how long it takes for the stone to hit
the canyon floor at the bottom of the cliff. But you're not asking for
anything after the stone barely misses the edge of the cliff on its way
down, and you're only asking about things that happen above the
edge of the cliff. So we don't need to know anything about the cliff,
or its height above anything else. The thrower might just as well be
standing in his front yard when he throws the stone straight up.
-- Gravity robs 9.8 m/s from the stone's upward speed every second.
So the stone reaches its maximum height, runs out of upward gas, and
starts falling, in (20 / 9.8) = <em>2.04 seconds</em> after the toss.
-- Its average speed during that time is (1/2) (20 + 0) = 10 m/s .
In 2.04 seconds at that average speed, it rises (2.04 x 10) = <em>20.4 meters</em> .
MAGNITUDE AND DIRECTION OF A VECTOR
Given a position vector →v=⟨a,b⟩,the magnitude is located by |v|=√a2+b2. The direction is equal to the angle formed with the x-axis, or with the y-axis, depending on the application. For a position vector, the direction is found by tanθ=(ba)⇒θ=tan−1(ba)
<h3>What is the formula of magnitude?</h3>
The formula to determine the extent of a vector (in two dimensional space) v = (x, y) is: |v| =√(x2 + y2). This formula is derived from the Pythagorean theorem. the procedure to determine the magnitude of a vector (in three dimensional space) V = (x, y, z) is: |V| = √(x2 + y2 + z2)
To learn more about magnitude and direction, refer
brainly.com/question/27248532
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main answer is given below,
Answer:

Explanation:
Work is the product of force and distance.

The force is 500 Newtons and the couch is raised 12 meters above the ground.
Substitute these values into the formula.

Multiply.

- 1 Newton meter is equal to 1 Joule.
- So, our answer of 6000 N*m equals 6000 J

The work done to move a 500 Newton couch 12 meters is <u>6000 Joules</u>. Therefore, choice D is correct.
Answer:
<h3><em>
468,000,000 m/s</em></h3>
Explanation:
According to newtons first law of motion;
Force = mass * acceleration
F = ma
where a = v-u/t
v is the final velocity
u is the initial velocity
t is the time taken
F = m(v-u/t)
Ft = m(v-u)
Given parameters;
F = 910,000N
t = 120m = 120 *60 = 7200secs
m = 1400kg
u = 0m/s
Required parameter
Final velocity v
Substituting the given parameters into the formula to get v;
Ft = m(v-u)
910,000 * 72000 = 1400(v-0)
910,000 * 72000 = 1400v
v = (910,000 * 72000)/1400
v = 910,000 * 720/14
v = 910,000 * 60
<em>v = 468,000,000 m/s</em>
<em></em>
<em>Hence the final velocity of the drag racer is 468,000,000 m/s</em>
Here As we can see the figure that the end of the rope is pulled by some force F
Now as we can see that Piano is connected by a pulley which is passing over the pulley so effectively net force on the piano upwards will be 2F as it is connected by 2 ropes by the pulley
Now for constant velocity of the piano we will say

since velocity is constant so acceleration must be ZERO
so here we have

as we know here that
mg = 1000 N
so we will have


so here force must be 500 N