Two friends are walking on a hot beach on a hot summer day. one friend reports her feet are becoming hot she needs her sandals.

A mover brings a box up the stairs in 10 seconds. If he applied a force of 20 N over a distance 10 m on the box, calculate the p

Softa [21]

Answer:

20 Watts

Explanation:

Work = force × distance

W = (20 N) (10 m)

W = 200 Joules

Power = work / time

P = 200 J / 10 s

P = 20 Watts

8 0

3 years ago

The center of mass of the system is the point at which the total mass of the system could be concentrated without changing the _

Sveta_85 [38]

The centre of mass of the system is the point at which the total

mass of system could be concentrated without changing the moment

of the system.

Centre of Mass is the point at which the whole mass of the system

is assumed to be concentrated.

The general formula for the COM is:

xₙ = Σmₐxₐ / Σmₐ where, a = 1,2,3.........n

Here the term Σ mₐ xₐ is called the first moment of the system and the

denominator expression is called total mass of the system.

Therefore, from this theory we can say that the moment of the system

remain unchanged while calculating the COM.

Hence, The centre of mass of the system is the point at which the total

mass of system could be concentrated without changing the moment

of the system.

learn more about centre of mass here:

brainly.com/question/3454419

#SPJ4

8 0

1 year ago

According to the Declaration, when do people have a right to revolution?

babunello [35]

Locke said that under natural law, all people have the right to life, liberty, and private property; under the social contract, the people could instigate a revolution against the government when it acted against the interests of citizens, to replace the government with one that served the interests of citizens.

3 0

2 years ago

A flat coil of wire consisting of 20 turns, each with an area of 50 cm2, is positioned perpendicularly to a uniform magnetic fie

jenyasd209 [6]

Answer:

0.5 A

Explanation:

N = 20, A = 50 cm^2 = 50 x 10^-4 m^2, dB = 6 - 2 = 4 T, dt = 2 s, R = 0.4 ohm

The induced emf is given by

e = - N dФ/dt

Where, dФ/dt is the rate of change of magnetic flux.

Ф = B A

dФ/dt = A dB/dt

so,

e = 20 x 50 x 10^-4 x 4 / 2 = 0.2 V

negative sign shows the direction of magnetic field.

induced current, i = induced emf / resistance = 0.2 / 0.4 = 0.5 A

5 0

3 years ago

A standing wave pattern is created on a string with mass density μ = 3.4 × 10-4 kg/m. A wave generator with frequency f = 61 Hz

uranmaximum [27]

Answer:

1) λ = 0.413 m , 2)v = 25,213 m / s , 3) T = 0.216 N , 4) m = 22.04 10-3 kg

Explanation:

1) The resonance occurs when the traveling wave bounces at the ends and the two waves are added, the ends as they are fixed have a node, the wavelength and the length of the string are related

λ = 2L / n n = 1, 2, 3 ...

In this case L = 0.62 m and n = 3

Let's calculate

λ = 2 0.62 / 3

λ = 0.413 m

2) the velocity related to wavelength and frequency

v = λ f

v = 0.413 61

v = 25,213 m / s

3) let's use the equation

v = √T /μ

T = v² μ

T = 25,213² 3.4 10⁻⁴

T = 0.216 N

4) the rope tension is proportional to the hanging weight

T-W = 0

T = W

W = m g

m = W / g

m = 0.216 / 9.8

m = 22.04 10-3 kg

5) n = 2

λ = 2 0.62 / 2

λ = 0.62 m

6) v = λ f

v = 0.62 61

v = 37.82 m / s

7) T = v² μ

T = 37.82² 3.4 10⁻⁴

T = 0.486 N

8) m = W / g

m = 0.486 / 9.8

m = 49.62 10⁻³ kg

9) n = 1

λ = 2 0.62

λ = 1.24 m

v = 1.24 61

v = 75.64 m / s

T = v² miu

T = 75.64² 3.4 10⁻⁴

T = 2.572 10⁻² N

m = 2.572 10⁻² / 9.8

m = 262.4 10⁻³ kg

5 0

3 years ago