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AleksAgata [21]
3 years ago
6

An iceskater is turning at a PERIOD of (1/3) second with his arms outstretched. a) What is his ANGULAR VELOCITY w? b) If he pull

s his arms towards his body to reduce his MOMENT OF INTERTIA by 1/2, what is his ANGULAR VELOCITY w? c) How much does his ROTATIONAL KINETIC ENERGY change? That is, if the initial Kinetic Energy is (KE)initial, what is the final KE? d) Where did that ENERGY come from, or go to?
Physics
1 answer:
Vikentia [17]3 years ago
4 0

Answer:

Explanation:

a )

Time period T = 1/3 s

angular velocity = 2π / T

= 2 x 3.14 x 3

ω = 18.84 radian / s

b )

Applying conservation of angular momentum

I₁ ω₁ = I₂ ω₂

I₁ / I₂ = ω₂ / ω₁

2 = ω₂ / ω

ω₂ = 2 ω

c )

(KE)initial = 1/2 I₁ ω²

(KE)final =  1/2 I₂ ω₂²

= 1/2 (I₁ / 2)  (2ω)²

=  I₁ ω²

c )

Change in rotational kinetic energy

=  I₁ ω² -  1/2 I₁ ω²

=  +  1/2 I₁ ω²

d )

This energy comes from the work done by centripetal force which is increased to increase the speed of rotation.

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adelina 88 [10]

Answer:

Answered

Explanation:

There are people out there who understand the value of insurance and want adequate coverage at a cheap rates. In my opinion, these are the best clients. You don't need to sell the person on the value of insurance; they all are ready  to understand it. In my opinion, it may be difficult to work with people who do not fully understand the value of insurance. These are the people who usually want necessary minimum coverage at the absolute inexpensive cost. However, when they need to make a claim  that they  are usually shocked to find out, feeling how they don't any coverage.

6 0
3 years ago
8. two +1 C charges are separated by 3000m. What is the magnitude of the electric force between them?
Sidana [21]

Answer:

1000 N

Explanation:

The magnitude of the electrostatic force between two charged object is given by

F=k\frac{q_1 q_2}{r^2}

where

k is the Coulomb constant

q1, q2 is the magnitude of the two charges

r is the distance between the two objects

Moreover, the force is:

- Attractive if the two forces have opposite sign

- Repulsive if the two forces have same sign

In this problem:

q_1=q_2=+1C are the two charges

r = 3000 m is their separation

Therefore, the electric force between the charges is:

F=(9\cdot 10^9)\frac{(1)(1)}{3000^2}=1000 N

8 0
3 years ago
What does velocity tell about movement
Kaylis [27]
<span>Velocity tells you what speed a moving object travels at and in what direction.</span>
3 0
3 years ago
Read 2 more answers
A solenoid is built with 870 turns uniformly distributed over a length of 0.390 m to produce a magnetic field of magnitude 1.00
Y_Kistochka [10]

Answer:

35.7 mA

Explanation:

The magnetic field inside a solenoid is given by:

B=\mu_0 I n (1)

where

\mu_0 = 4\pi \cdot 10^{-7} H/m is the vacuum permeability

I is the current

n is the number of turns per unit length

Since we have

N = 870 turns

L = 0.390 (length of the solenoid)

we can calculate n

n=\frac{N}{L}=\frac{870}{0.390}=2230.8

And now we can re-arrange eq.(1) to find the current, I:

I=\frac{B}{\mu_0 n}=\frac{1.00\cdot 10^{-4} T}{(4\pi\cdot 10^{-7} H/m)(2230.8m^{-1})}=0.0357 A = 35.7 mA

6 0
3 years ago
Which of the following is TRUE regarding Softball?
Y_Kistochka [10]

Answer:

There are two popular forms of softball, distinguished by the type of pitch.

Explanation:

Softball refers to a kind of sports that is similar to baseball in terms of game play but softball is played with a larger ball. The game of softball was first introduced as an indoor game in Chicago, Illinois, United States of America in the year 1887. Also, the field for playing softball is relatively smaller than that of baseball and as such its game play is quite faster.

Some of the kits and paraphernalia used for playing softball are base, bat, softball, gloves, jerseys etc.

There are two (2) main types of softball game and these are;

I. Fast-pitch softball.

II. Slow-pitch softball.

Hence, the true statement regarding softball is that, there are two popular forms of softball, distinguished by the type of pitch.

7 0
3 years ago
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