Why doesn't the arrow fly forever

A swimmer bounces almost straight up from a diving board and falls vertically feet first into a pool.she starts with a speed of

garik1379 [7]

Answer:

a) 1.20227 seconds

b) 0.98674 m

c) 7.3942875 m/s

Explanation:

t = Time taken

u = Initial velocity = 4.4 m/s

v = Final velocity

s = Displacement

a = Acceleration due to gravity = 9.81 m/s²

$v=u+at\\\Rightarrow 0=4.4-9.81\times t\\\Rightarrow \frac{-4.4}{-9.81}=t\\\Rightarrow t=0.44852\ s$

$s=ut+\frac{1}{2}at^2\\\Rightarrow s=4.4\times 0.44852+\frac{1}{2}\times -9.81\times 0.44852^2\\\Rightarrow s=0.98674\ m$

b) Her highest height above the board is 0.98674 m

Total height she would fall is 0.98674+1.8 = 2.78674 m

$s=ut+\frac{1}{2}at^2\\\Rightarrow 2.78674=0t+\frac{1}{2}\times 9.81\times t^2\\\Rightarrow t=\sqrt{\frac{2.78674\times 2}{9.81}}\\\Rightarrow t=0.75375\ s$

a) Her feet are in the air for 0.75375+0.44852 = 1.20227 seconds

$v=u+at\\\Rightarrow v=0+9.81\times 0.75375\\\Rightarrow v=7.3942875\ m/s$

c) Her velocity when her feet hit the water is 7.3942875 m/s

3 0

3 years ago

in which of the exercise and sports science do specialist study achievement motivation , arousal attribution and personality dev

Mekhanik [1.2K]

Sport and exercise psychology

Explanation:

Here you study the psychological factors that are connected to your performance and contribution to sport, exercises and physical activities.Through application of psychological principles you can attain higher mental health and your performance will be enhanced. For example, you will be able to recognize times when you experience emotional states without without knowing the reasons or causes which is a concept of arousal attribution.Understanding your pattern of behavior and attitude builds up your personality making you distinctive.

Learn More

Sports and exercise psychology :brainly.com/question/1213874

Keywords : exercise, sports science, study , achievement motivation, arousal attribution, personal development.

#LearnwithBrainly

7 0

3 years ago

Several light bulbs, each of resistance 1.5 Ω, are connected in a series across a 120 V source of emf. If the current through th

Leni [432]

<h3><u>Answer;</u></h3>

40 light bulbs

<h3><u>Explanation</u>;</h3>

The total resistance of components or bulbs in series is given as the sum of resistance of all the components.

Thus; if there are bulbs in series each with a resistance of 1.5 Ω, the the total resistance will be; 1.5nΩ

From the ohms law;

V = IR , where V is the voltage, I is the current and R is the resistor.

Thus; R = V/i

R = 120/2

= 60 Ω

But, there are n bulbs each with 1.5 Ω; thus there are;

n = 60/1.5

<u> = 40 Bulbs </u>

7 0

2 years ago

A refrigerator is used to remove 84 kj/min of heat from a tank. If the electric power consumed by the refrigerator is 1. 2 kw, w

zvonat [6]

Answer:

84 kj/min = 1.4 kj/sec

Power Out / Power In = Heat Out / Heat In - Coefficient of Performance

1.4 kj/sec / 1.2 kj/sec = 1.17 = COP

3 0

2 years ago

In a thunderstorm at 20.0°C, Karen sees a bolt of lightning and hears the thunderclap 3.00 s later. How far from Karen did the l

Minchanka [31]

-- The speed of light in air is very close to 3 x 10⁸ m/s.
Whatever the actual number is, it's equivalent to roughly
7 times around the Earth in 1 second. So for this kind of
problem, you can assume that we see things at the same time
that they happen; don't bother worrying about how long it takes
for the light to reach you.

-- For sound, it's a different story. Sound in air only travels at
about 340 m/s. It takes sound almost 5 seconds to go 1 mile.

-- Now, the lightning and thunder happen at the same time.
The light travels to you at the speed of light, so you see the
lightning pretty much when it happens. But the sound of the
thunder comes poking along at 340 m/s, and arrives AFTER
the sight of the lightning.

The length of time between the sight and the sound is about
99.9999% the result of the time it takes the sound to reach you.

If the thunder arrived at you 3 seconds after the light did, then
the sound traveled

   (340 m/s) x (3 s) = 1,020 meters .
    (about 0.63 of a mile)

(If you're worried about ignoring the time it takes
for the light to reach you ...

It takes light 0.0000034 second to cover the same 1,020 meters,

so including it in the calculation would not change the answer.)

7 0

3 years ago