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2 years ago

A man of mass 85 kg runs up a flight of stairs of height 4.6 m in a time period

Physics

1 answer:

seraphim [82]2 years ago

7 0

Explanation:

a) Power = work / time = force × distance / time

P = Fd/t

P = (85 kg × 9.8 m/s²) (4.6 m) / (12 s)

P ≈ 319 W

b) P = Fd/t

0.70 (319 W) = (m × 9.8 m/s²) (4.6 m) / (9.6 s)

m = 47.6 kg

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If a train is 100 kilometers away, how much sooner would you hear the train coming by listening to the rails (iron) as opposed t

Whitepunk [10]

From tables, the speed of sound at 0°C is approximately
V₁ = 331 m/s (in air)
V₃ = 5130 m/s (in iron)

Distance traveled is
d = 100 km = 10⁵ m

Time required to travel in air is
t₁ = d/V₁ = 10⁵/331 = 302.12 s

Time required to travel in iron is
t₂ = d/V₂ = 10⁵/5130 = 19.49 s

The difference in time is
302.12 - 19.49 = 282.63 s

Answer: 283 s (nearest second)

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2 years ago

A uniform cylindrical steel wire (density: 7.8 x 103 kg/m3), 58.0 cm long and 1.34 mm in diameter, is fixed at both ends. To wha

lbvjy [14]

Answer:

T= 354.65 N

Explanation:

Given that

ρ= 7800 kg/m³

L= 58 cm

d=1.34 mm

f= 311 Hz

T= Tension

Speed of wave ,V

V = f λ

V = f L

V= 311 x 0.58 m/s

V=180.38 m/s

Area of cross sectional

A= πr² mm²

A= 3.14 x 0.67² mm²

A=1.41 mm²

Mass = Density x Volume

$m=7800\times 1.41\times 10^{-6}\ kg/m$

m=0.0109 kg/m

Tension ,T

$T=m V^2$

T= 0.0109 x 180.38² N

T= 354.65 N

3 0

2 years ago

Find the intensity in decibels [i(db)] for each value of i. normal conversation: i = 106i0 i(db) = power saw a 3 feet: i = 1011i

White raven [17]

Answer:

Normal Conversation: i=106i0

i(dB)=60

Power saw a 3 feet: i=1011i0

i(dB)=110

Jet engine at 100 feet: i=1018i0

i(dB)=180

Explanation:

if these are the same as edge, then these are the answers! :)

8 0

2 years ago

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The magnetic field around the head has been measured to be approximately 3.00×10−8 gauss . Although the currents that cause this

konstantin123 [22]

Answer:

$3.81972\times 10^{-7}\ A$

Explanation:

B = Magnetic field = $3\times 10^{-8}\ G$

d = Diameter of loop = 16 cm

r = Radius = $\frac{d}{2}=\frac{16}{2}=8\ cm$

i = Current

$\mu_0$ = Vacuum permeability = $4\pi \times 10^{-7}\ H/m$

The magnetic field of a loop is given by

$B=\frac{\mu_0i}{2r}\\\Rightarrow i=\frac{B2r}{\mu_0}\\\Rightarrow i=\frac{3\times 10^{-8}\times 10^{-4}\times 2\times 0.08}{4\pi\times 10^{-7}}\\\Rightarrow i=3.81972\times 10^{-7}\ A$

The current needed to produce such a field at the center of the loop is $3.81972\times 10^{-7}\ A$

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2 years ago

Two male moose charge at each other with the same speed and meet on a icy patch of tundra. As they collide, their antlers lock t

Ksenya-84 [330]

Change in velocity of larger moose: (1/3)v - v = -(2/3)v
<span>change in velocity of small moose: (1/3)v - (-v) = (4/3)v </span>
<span>- (change in velocity of larger moose)/(change in velocity of smaller moose) = 2

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4 0

2 years ago

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