Explanation:
Mass of the ball, m = 0.058 kg
Initial speed of the ball, u = 11 m/s
Final speed of the ball, v = -11 m/s (negative as it rebounds)
Time, t = 2.1 s
(a) Let F is the average force exerted on the wall. It is given by :


F = 0.607 N
(b) Area of wall, 
Let P is the average pressure on that area. It is given by :


P = 0.202 Pa
Hence, this is the required solution.
Displacement is d
Vf² = Vi² + 2 g d
(-20²) = (+10²) + 2 (-9.8) d
-19.6 d = 300
d = -15.3 m
negative means lower
time is t
d = Vi t + 1/2 g t²
-15.3 = 10 t + (-4.9) t²
4.9 t² - 10 t -15.3 = 0
t = 3.06 s
Hope this helps -John
Answer:
61440 peaks
Explanation:
A hertz represents one cycle for every second:

So if a wave have frequency of 2Hz for example, this means the wave does two cycles per second.
Normally the waves are represented by cosine or sine waves. These kind of waves have two peaks in each cycle, one positive and one negative. With this in mind, let's calculate how many peaks of the wave pass each minute.
A minute has 60 seconds, hence:

And we know already that every cycle has two peaks, so:

<span>Usually, If you drop a 200 gram piece of metal with a temperature of 110 degrees Celsius into 1000 grams of water at 25° Celsius, the statement which would best describe what would occur is the last one : </span><span>The water and the metal's temperatures will reach the same temperature. I choose this one because this is a nice example of how the nature tries to reach the balance. Hope it helps! Regards.</span>
The value of the thrust developed by the engine of a boeing 777 in N and Kgf are ;
i) 376616N
ii) 38430Kgf
<h3>What is force?</h3>
Force is a push or a pull. The reactive force always serve to balance the applied force. We are here asked to convert the the thrust developed by the engine of a boeing 777 which is about 85400 lbf to the following units;
i) N
ii)kgf
Thus;
1 Ib = 0.45 Kg
1 lbf = 0.45 Kg * 9.8 m/s^2 = 4.41 N
We know that;
1 lbf = 4.41 N
85400 lbf = 85400 lbf. * 4.41 N/1 lbf
= 376616N
Again;
1 lbf = 0.45 Kgf
85400 lbf = 85400 lbf * 0.45 Kgf/1 lbf
= 38430Kgf
Learn more about force:brainly.com/question/13191643
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