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3 years ago

What determines whether or not work is being done?

1 answer:

3 0

C is the correct answer but the best possible answer is that work is done when a force is imposed on an object and the object moves in the same direction as the force

Hope this helps!

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Tendons are strong elastic fibers that attach muscles to bones. To a reasonable approximation, they obey Hooke's law. In laborat

meriva

Answer:

k = 200 N/m

Explanation:

given,

mass of the object = 251 g

= 251 x 10⁻³ Kg = 0.251 Kg

distance of tendon stretch = x = 1.23 cm

= 1.23 x 10⁻² = 0.0123 m

using the formula

F = k x

where

k is the force constant of the tendon

F = m g

F = 0.251 x 9.8 = 2.4598 N

2.4598 = k x 0.0123

k = 199.98 N/m

k = 200 N/m

hence, force constant of the tendon is approximately equal to 200 N/m

5 0

3 years ago

Expectant mothers many times see their unborn child for the first time during an ultrasonic examination. In ultrasonic imaging,

katrin2010 [14]

Answer:

380 kHz

Explanation:

The speed of sound is taken as 1500 m/s

The length of the fetus is 1.6 cm long

The condition is that the wavelength used must be at most 1/4 of the size of the object that is to be imaged.

For this 1.6 cm baby, the wavelength must not exceed

λ = $\frac{1}{4}$ of 1.6 cm = $\frac{1}{4}$ x 1.6 cm = 0.4 cm =

0.4 cm = 0.004 m this is the wavelength of the required ultrasonic sound.

we know that

v = λf

where v is the speed of a wave

λ is the wavelength of the wave

f is the frequency of the wave

f = v/λ

substituting values, we have

f = 1500/0.004 = 375000 Hz

==> 375000/1000 = 375 kHz ≅ 380 kHz

4 0

3 years ago

Select all of the answers that apply.

galben [10]

The answers are --

a) wind direction
b) wind speed
e) intensity of precipitation
f) location of precipitation

6 0

3 years ago

Read 2 more answers

Which kind of good might not be bought when prices rise?

IgorC [24]

luxury goods might not be bought

5 0

3 years ago

Read 2 more answers

A heat engine performs (245 + A) J of work in each cycle while also delivering (142 + B) J of heat to the cold reservoir. Find t

Ganezh [65]

Answer:

The value is $\eta = 54.4 \%$

Explanation:

From the question we are told that

The work input is $W = ( 245 + A ) \ J$

The heat delivered is $Q = (142 + B) \ J$

The value of A is A = 14

The value of B is B = 72

Generally the efficiency of the heat engine is mathematically represented as

$\eta = \frac{W}{Q_t}$

Here $Q_t$ is the total out energy produce by the heat engine and this is mathematically represented as

$Q_t= Q + W$

=> $Q_t= 245 + A + 142 + B$

=> $Q_t= 390 + A+B$

$\eta = \frac{245 + A }{390 + A+ B}$

=> $\eta = 0.544$

=> $\eta = 0.544 *100$

=> $\eta = 54.4 \%$

5 0

3 years ago