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Ronch [10]
4 years ago
14

A girl runs up the down escalator in the mall. If the escalator is moving with a

Physics
1 answer:
Scilla [17]4 years ago
4 0

Answer:

D. 24 m

Explanation:

Running up - velocity     + 30 m/min

Escalator 's moving down  velocity   - 24 m/min

Sum velocity (30 - 24) = 6 m/min

6 m/min * 4 min = 24 m

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Which part of the wave has the highest frequency?
trapecia [35]

Answer:

The last part on the right side of the diagram

Explanation:

Im on plato and just got it right :)

6 0
3 years ago
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A horizontal 810-N merry-go-round of radius 1.60 m is started from rest by a constant horizontal force of 55 N applied tangentia
Sloan [31]

Answer:

576 joules

Explanation:

From the question we are given the following:

weight = 810 N

radius (r) = 1.6 m

horizontal force (F) = 55 N

time (t) = 4 s

acceleration due to gravity (g) = 9.8 m/s^{2}

K.E = 0.5 x MI x ω^{2}

where MI is the moment of inertia and ω is the angular velocity

MI = 0.5 x m x r^2

mass = weight ÷ g = 810 ÷ 9.8 = 82.65 kg

MI = 0.5 x 82.65 x 1.6^{2}

MI = 105.8 kg.m^{2}

angular velocity (ω) = a x t

angular acceleration (a) = torque ÷ MI

where torque = F x r = 55 x 1.6 = 88 N.m

a= 88 ÷ 105.8 = 0.83 rad /s^{2}

therefore

angular velocity (ω) = a x t = 0.83 x 4 = 3.33 rad/s

K.E = 0.5 x MI x ω^{2}

K.E = 0.5 x 105.8 x 3.33^{2} = 576 joules

6 0
3 years ago
Find the wavelength λ of the 80.0-khz wave emitted by the bat. express your answer in millimeters.
vfiekz [6]

Answer:

4.29 millimeters

Explanation:

Bats emit ultrasound waves: in air, ultrasound waves travel at a speed of

v=343 m/s

The frequency of the waves emitted by this bat is:

f=80.0 kHz = 80,000 Hz

Therefore we can find the wavelength of the wave emitted by the bat by using the relationship between speed, frequency and wavelength:

\lambda=\frac{v}{f}=\frac{343 m/s}{80,000 Hz}=4.29\cdot 10^{-3} m=4.29 mm

4 0
3 years ago
A car with a mass of 1.50x10^3 kg starts from rest and accelerates to a speed of 18.0m/s in 12.0 s. assume that the force of res
Luden [163]
The first thing you should know for this case is the definition of distance.
 d = v * t
 Where,
 v = speed
 t = time
 We have then:
 d = v * t
 d = 9 * 12 = 108 m
 The kinetic energy is:
 K = ½mv²
 Where,
 m: mass
 v: speed
 K = ½ * 1500 * (18) ² = 2.43 * 10 ^ 5 J
 The work due to friction is
 w = F * d
 Where,
 F = Force
 d = distance:
 w = 400 * 108 = 4.32 * 10 ^ 4
 The power will be:
 P = (K + work) / t
 Where,
 t: time
 P = 2.86 * 10 ^ 5/12 = 23.9 kW
 answer:
 the average power developed by the engine is 23.9 kW
8 0
3 years ago
Four students made a graphic organizer describing the parts of the atom.
Nikitich [7]

Answer:

I believe the answer is D.

Explanation:

Protons are found inside the nucleus so are neutrons. Electrons are found outside the nucleus.

8 0
3 years ago
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