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STALIN [3.7K]
3 years ago
9

A skater makes one revolution per second, f = w/(2p) = 1, with her arms and leg stretched (left). By lowering her leg and bringi

ng her arms close to her chest (right) she reduces her moment of inertia from I to I′ = 0.4I. How many revolutions per second, f′ = w¢/(2p), is she making now? Show all your work.
Physics
2 answers:
mihalych1998 [28]3 years ago
8 0

Answer:

f'=w'/2p=2.49rev/s

Explanation:

The angular momentum L must be equal for both cases.

Hence you have that

L before = L after

L=I\omega

\omega=2\pi f

I = moment of inertia

w =angular momentum

Hence

L=L'\\I\omega =I'\omega'\\\omega'=\frac{I\omega}{I'}=\frac{I*2\pi *1}{0.4I}=15.70\frac{rad}{s}

f'=w'/2p=2.49rev/s

hope this helps!!

Firlakuza [10]3 years ago
4 0

Answer:

Answer is given in the attachment.

Explanation:

Download pdf
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One problem for humans living in outer space is that they are apparently weightless. One way around this problem is to design a
Maurinko [17]

This question is not complete.

The complete question is as follows:

One problem for humans living in outer space is that they are apparently weightless. One way around this problem is to design a space station that spins about its center at a constant rate. This creates “artificial gravity” at the outside rim of the station. (a) If the diameter of the space station is 800 m, how many revolutions per minute are needed for the “artificial gravity” acceleration to be 9.80m/s2?

Explanation:

a. Using the expression;

T = 2π√R/g

where R = radius of the space = diameter/2

R = 800/2 = 400m

g= acceleration due to gravity = 9.8m/s^2

1/T = number of revolutions per second

T = 2π√R/g

T = 2 x 3.14 x √400/9.8

T = 6.28 x 6.39 = 40.13

1/T = 1/40.13 = 0.025 x 60 = 1.5 revolution/minute

6 0
3 years ago
Which location on the map above is a source of North Atlantic deep water?
bija089 [108]
The answer might be C ? hope it's right
4 0
3 years ago
Potential difference of a battery is 2.2 V when it is connected
Alchen [17]

Answer:

1.1ohms

Explanation:

According to ohms law E = IR

If potential difference of a battery is 2.2 V when it is connected across a resistance of 5 ohm and if suddenly the voltage Falls to 1.8V then the current in the 5ohms resistor I = V/R = 1.8/5

I = 0.36A (This will be the load current).

Before we can calculate the value of the internal resistance, we need to know the voltage drop across the internal resistance.

Voltage drop = 2.2V - 1.8V = 0.4V

Then we calculate the internal resistance using ohms law.

According to the law, V = Ir

V= voltage drop

I is the load current

r = internal resistance

0.4 = 0.36r

r = 0.4/0.36

r = 1.1 ohms

6 0
4 years ago
An 800-kHz radio signal is detected at a point 8.5 km distant from a transmitter tower. The electric field amplitude of the sign
Temka [501]

Answer:

Explanation:

Given that,

Frequency of radio signal is

f = 800kHz = 800,000 Hz.

Distance from transmitter

d = 8.5km = 8500m

Electric field amplitude

E = 0.9 V/m

The average energy density can be calculated using

U_E = ½•ϵo•E²

Where ϵo = 8.85 × 10^-12 F/m

Then,

U_E = ½ × 8.85 × 10^-12 × 0.9²

U_E = 3.58 × 10^-12 J/m²

The average electromagnetic energy density is 3.58 × 10^-12 J/m²

6 0
3 years ago
Read 2 more answers
A wooden log is displaced to a distance of 20m in 10 seconds by applying 500N effort . Calculate the workdone and power.​
nata0808 [166]

A wooden log is displaced to a distance of 20m in 10 seconds by applying 500N effort . Calculate the workdone and power...

Solution,

displacement = 20 m

time = 10 sec

force = 500 N

work done = ?

power = ?

Now ,

work done = f × s

= 500 N × 20 m

= 10000 j

Now ,

power \:  =  \frac{w}{t}  \\  =  \frac{10000j}{10sec}  \\   = 1000W

~nightmare 5474~

8 0
3 years ago
Read 2 more answers
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