Ask question

Ask question

All categories

3 years ago

13

An ice skater has a moment of inertia of 5.0 kg · m2when her arms are outstretched, and at this time she is spinning at 3.0 rev/

s. If she pulls in her arms and decreases her moment of inertia to 2.0 kg · m2, how fast will she be spinning?

1 answer:

KatRina [158]3 years ago

8 0

Answer:

Explanation:

Given

Initial Moment of Inertia $I_1=5 kg-m^2$

initial Spin $N_1=3 rev/s$

$\omega _1=2\pi N_1=2\pi 3=6\pi rad/s$

Final Moment Moment of Inertia $I_2=2 kg-m^2$

Conserving Angular momentum

$L_1=L_2$

$I_1\omega _1=I_2\omega _2$

$5\times 6\pi=2\times \omega _2$

$\omega _2=15\pi rad/s$

$N_2=\frac{\omega _2}{2\pi }$

$N_2=\frac{15\pi }{2\pi}=7.5 rev/s$

You might be interested in

Both high-side pressures and low-side pressures are low with the engine running and the selector set to the air-conditioning pos

elena-14-01-66 [18.8K]

Answer:

Technician A only

Explanation:

Both high-side pressures and low-side pressures are low with the engine running and the selector set to the air-conditioning position. Technician A says that the system is undercharged. Technician B says the cooling fan could be inoperative. Which technician is correct?

usually . An overcharged system will result in lower than normal low side pressures

An undercharged system will not enable the compressor to create pressure. As a result of the low amount of refrigerant, the cooling ability is reduced. When we say undercharged, we mean the refrigerant in the system is low, so the both the high side pressures and low side pressures will be low.

8 0

2 years ago

A charge of 8.5 × 10–6 C is in an electric field that has a strength of 3.2 × 105 N/C. What is the electric force acting on the

Sonja [21]

2.72 N

Explanation:

Step 1:

From the basic formula in electrostatics

F = E * q

where F = Force due to charges

E = Electric field strength

q = Charge

Step 2:

From the given question

q= $8.5*10^{-6} C$

E = $3.2 * 10^{5} N/C$

F = $8.5 * 10^{-6} * 3.2 * 10^{5} = 2.72$ N

8 0

3 years ago

In the absence of air resistance, at what other angle will a thrown ball go the same distance as one thrown at an angle of 75 de

snow_tiger [21]

As we know that range of the projectile motion is given by

$R = \frac{v^2 sin(2\theta)}{g}$

here we know that range will be same for two different angles

so here we can say the two angle must be complementary angles

so the two angles must be

$\theta, 90 - \theta$

so it is given that one of the projection angle is 75 degree

so other angle for same range must be 90 - 75 = 15 degree

so other projection angle must be 15 degree

5 0

2 years ago

Analyze data table #1 and then create a line graph comparing speed and time.

In-s [12.5K]

I don’t know what the answer is to the question but if I don’t answer the question I will be mad at the

8 0

3 years ago

If a 3.5 gram ping pong ball were traveling to the right horizontally at 12 m/s, and a larger 12 g super ball were thrown direct

algol [13]

Answer:

v = 14.32 m/s

Explanation:

According to the principle of conservation of linear momentum, both the momentum and kinetic energy of the system are conserved. Since the two balls are in the same direction of motion before collision, then;

$m_{1} u_{1}$ + $m_{2} u_{2}$ = ( $m_{1}$ + $m_{2}$ ) v

0.035 × 12 + 0.120 × 15 = (0.035 + 0.120) v

0.420 + 1.800 = (0.155) v

2.22 = 0.155 v

⇒ v = $\frac{2.22}{0.155}$

= 14.323

The velocity of the balls after collision is 14.32 m/s.

3 0

3 years ago