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Can you help me with a science test

Semenov [28]

Answer:

yes just give me questions and put me brainliest

Explanation:

8 0

3 years ago

Read 2 more answers

A tennis ball is released from a height of 4.0 m above the floor. After its third bounce off the floor, it reaches a height of 1

diamong [38]

Answer:

The percentage of its mechanical energy does the ball lose with each bounce is 23 %

Explanation:

Given data,

The tennis ball is released from the height, h = 4 m

After the third bounce it reaches height, h' = 183 cm

= 1.83 m

The total mechanical energy of the ball is equal to its maximum P.E

E = mgh

= 4 mg

At height h', the P.E becomes

E' = mgh'

= 1.83 mg

The percentage of change in energy the ball retains to its original energy,

$\Delta E\%=\frac{1.83mg}{4mg}\times100\%$

ΔE % = 45 %

The ball retains only the 45% of its original energy after 3 bounces.

Therefore, the energy retains in each bounce is

∛ (0.45) = 0.77

The ball retains only the 77% of its original energy.

The energy lost to the floor is,

E = 100 - 77

= 23 %

Hence, the percentage of its mechanical energy does the ball lose with each bounce is 23 %

5 0

4 years ago

The tub of a washing machine goes into its spin cycle, starting from rest and gaining angular speed steadily for 10.0 s, at whic

ioda

Answer:

69 revolutions

Explanation:

given,

initial angular velocity = 0

final angular velocity = 6 rev/s

when safety switch turned off

tub smoothly slows to rest in (t)= 13 s

total revolution of tub = ?

angular acceleration = $\dfrac{\omega_f-\omega_0}{t}$

angular acceleration = $\dfrac{6-0}{10}$

= 0.6 rev/s²

now,

$\theta = \omega_i t +\dfrac{1}{2}\alpha t^2$

$\theta = 0+\dfrac{1}{2}\times 0.6 \times 10^2$

= 30 revolution

now,

when safety switch turn off

angular acceleration = $\dfrac{\omega_f-\omega_0}{t}$

angular acceleration = $\dfrac{0-6}{13}$

= -0.462 rev/s²

now,

$\theta = \omega_i t +\dfrac{1}{2}\alpha t^2$

$\theta = 6 \times 13 -\dfrac{1}{2}\times 0.462 \times 13^2$

= 39 revolution

total revolution = 30 + 39 = 69 revolutions.

tub will rotate 69 revolutions

4 0

3 years ago

In the final stages of production, a pharmaceutical is sterilized by heating it from 25 to 75C as it moves at 0.2 m/s through a

steposvetlana [31]

Answer:

The answer is " $12682.267\ \ \frac{W}{m^2}$ "

Explanation:

Calculating the mass flow rate of fluid:

$m= \rho AV$

$= \rho \frac{\pi}{4} D^2\ V\\\\= 100 \times \frac{\pi}{4} \times (0.0127)^2\times 0.2\\\\=0.0253 \ \frac{kg}{s}\\\\$

Calculating the amount of heat transfer.

$q =m\timesC_p(T_{m,0}-T_{m,i})$

$=0.0253 \times 4000 (75-25)\\\\=0.0253 \times 4000(50)\\\\=0.0253 \times 200,000 \\\\= 5060 \ W$

Calculating the required value for heat flux:

$q"=\frac{q}{A_s}$

$=\frac{q}{\pi DL}\\\\= \frac{5060}{\pi \times 0.0127 \times 10}\\\\= 12682.267 \frac{W}{m^2}\\$

3 0

3 years ago

What is the relationship between the structure of a white blood cell and its function in the body.

mario62 [17]

White blood cell,also called leukocyte or white corpuscle,a cellular component of the blood that lacks hemoglobin,has a nucleus,is capable of motility,and defends the body against infection and disease by ingesting foreign materials and cellular debris,by destroying infectious agents and cancer cells.

6 0

3 years ago