Friction is a ____________ force<br> a. Artificial<br> b. Natural<br> c. Pessimistic<br> d. Negative

Use the drop-down menus to complete the statements.

MaRussiya [10]

Answer:

1- experimental

2-descriptive

3-comparative

Explanation:

just did it

4 0

3 years ago

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A person is pushing a box.The net external force on the 60-kg box is stated to be 90 N. If the force of friction opposing the mo

Trava [24]

Answer:

a = 1 m/s²

Explanation:

given,

mass of the person = 60 Kg

Net External force exerted = 90 N

force of friction opposing the motion = 30 N

acceleration of the box = ?

Net force = External force applied - frictional force

Net force = 90 - 30

net force = 60 N

we know

F = mass x acceleration

60 = 60 x a

a = 1 m/s²

acceleration of the box is equal to a = 1 m/s²

7 0

3 years ago

Water at 20oC flows through a long elliptical duct 30 cm wide and 22 cm high. What average velocity, in m/s, would cause the wei

mars1129 [50]

Explanation:

The given data is as follows.

Fluid is water so, density $\rho = 1000 kg/m^{3}$

Weight flow rate = 500 lbf/s = 2224.11 N/sec

Cross-sectional area (A) = $\pi \times \frac{30}{2} \times \frac{22}{2}$

= 0.05184 $m^{2}$

Hence, weight flow rate will be given as follows.

w = $\rho \times g \times A \times V$

2224.11 N/sec = $\rho \times g \times A \times V$

V = $\frac{2224.11}{1000 \times 9.81 \times 0.05184}$ m/s

= 4.373 m/s

Thus, we can conclude that average velocity in the given case is 4.373 m/s.

8 0

3 years ago

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A wave has a wavelength of 4. 9 m and a velocity of 9. 8 m/s. The medium through which this wave is traveling is then heated so

tatiyna

The wavelength of a wave is obtained by taking the ratio of wave speed and frequency.

The wavelength of the heated wave is 9.8 m. Hence, option (b) is correct.

What is frequency of a wave?

The number of oscillations completed by a wave in one second is known as the frequency of a wave. It is expressed as the ratio of the velocity of the wave to its wavelength.

Given data-

The wavelength of the wave is, $\lambda = 4.9 \;\rm m$ .

The velocity of the wave is, v = 9.8 m/s.

The mathematical expression for the frequency of the wave is,

$f = \dfrac{v}{\lambda}$

Solving as,

$f = \dfrac{9.9}{4.9}\\\\f =2 \;\rm Hz$

Now, with constant frequency and the double magnitude of velocity (v' = 2 × 9.8 = 19.6 m/s). The wavelength of the heated wave is calculated as,

$f = \dfrac{v'}{\lambda'}$

here,

$\lambda'$ is the wavelength of the heated wave.

Solving as,

$2 = \dfrac{19.6}{\lambda'}\\\\\lambda' = \dfrac{19.6}{2}\\\\\lambda' = 9.8 \;\rm m$

Thus, we can conclude that the wavelength of the heated wave is 9.8 m. Hence, option (b) is correct.

Learn more about the frequency of wave here:

brainly.com/question/1324797

3 0

2 years ago

A common carnival ride, called a gravitron, is a large r = 11 m cylinder in which people stand against the outer wall. the cylin

Elena-2011 [213]

Answer:

The minimum speed is 14.53 m/s.

Explanation:

Given that,

r = 11 m

Friction coefficient = 0.51

Suppose we need to find the minimum speed, that the cylinder must make a person move at to ensure they will stick to the wall

When frictional force becomes equal to or greater than the weight of person

Then, he sticks to the wall

We need to calculate the minimum speed

Using formula for speed

$f_{s}=\mu N\geq mg$

Where, $N =\dfrac{mv^2}{r}$

$\mu\times\dfrac{mv^2}{r}\gep mg$

$v^2\geq\dfrac{gr}{\mu}$

Put the value into the formula

$v=\sqrt{\dfrac{9.8\times11}{0.51}}$

$v=14.53\ m/s$

Hence, The minimum speed is 14.53 m/s.

8 0

3 years ago

Friction is a ____________ force a. Artificial b. Natural c. Pessimistic d. Negative