Convert the following.

What happens when a spinning ice skater draws in her outstretched arms? Group of answer choices Her moment of inertia increases

kotegsom [21]

Answer:

Her moment of inertia decreases causing her spin to speed up. The physics law behind this phenomenon is the conservation of angular momentum.

Explanation:

<em>Theory</em>

<u>The Law of conservation of angular momentum</u>

The angular momentum of a rotating body or a system remains constant unless it is acted upon by an external unbalance force.

Angular momentum = moment of inertia × angular velocity

The moment of inertia = mass×[perpendicular distance from axis of rotation]²

___________________________________________________________

⇒When skater draws in her outstretched arms the mass distribution get concentrated towards the axis of rotation so the moment of inertia of the body decrease.

But angular moment should conserve so angular velocity increases (spin increases)

5 0

3 years ago

A current 2a flows in a circuit fir 2 minutes. Calculate the charge generated in a circuit

nirvana33 [79]

Answer:

the charge generated in the circuit is 240 C.

Explanation:

Given;

current flowing in the circuit, I = 2A

time of current flow, t = 2 minutes = 2 x 60s = 120 s

The current flowing through a given circuit is defined as the quantity of charge flowing through the circuit in a given time.

$I = \frac{Q}{t} \\\\Q = I t$

where;

Q is the charge flowing in the circuit

Q = 2 x 120

Q = 240 C

Therefore, the charge generated in the circuit is 240 C.

3 0

4 years ago

Which list of factors best supports the concept that they are "just right" for the planet earth to support life?

Ivanshal [37]

Temperature, gravity, atmosphere and water

8 0

3 years ago

Read 2 more answers

A hockey puck is sliding across a frozen pond with an initial speed of 9.5 m/s. It comes to rest after sliding a distance of 37.

Bond [772]

Answer:

<h3>The coefficient of kinetic friction between the puck and the ice is $\mu _{k} =$ 0.12</h3>

Explanation:

Given :

Initial speed $v_{o} = 9.5 \frac{m}{s}$

Displacement $x = 37.4$ m

From the kinematics equation,

$v^{2} - v^{2} _{o} = 2ax$

Where $v^{2} =$ final velocity, in our example it is zero ( $v =0$ ), $a =$ acceleration.

$a =- \frac{90.25}{ 2 \times 37.4}$

$a =- 1.21 \frac{m}{s^{2} }$

From the formula of friction,

$F =- \mu _{k } N$

Minus sign represent friction is oppose the motion

Where $N = mg$ ( normal reaction force )

$ma = -\mu _{k} m g$ ( ∵ $g = 9.8 \frac{m}{s^{2} }$ )

So coefficient of friction,

$\mu_{k} = \frac{1.21}{9.8}$

$\mu_{k} = 0.12$

Therefore, the coefficient of kinetic friction between the puck and the ice is $\mu _{k} =$ 0.12 .

4 0

3 years ago

One of Lex Luthor's henchman attacks Superman, shooting a rapid-fire stream of 3.3 g bullets at him at a rate of 112/min. The sp

igor_vitrenko [27]

Answer:

3.2451N

Explanation:

Mass of the bullet (m) $= 3.3g = 3.3*10^{-3}Kg$

Speed of the bullet (V) $= 527m/s$

Rate of bullet (r) $= 112/min = 1.866\sec$

We can calculate with this information the average acceleration of bullets

$a=V*r = 527\frac{m}{s}\frac{1.866}{s} = 983.38m/s^2$

The force is given by,

$F=ma\\F=(3.3*10^{-3})*983.38m/s^2 = 3.2451N$

That is just because he is Superman.

4 0

3 years ago