1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
vichka [17]
2 years ago
7

A playground merry-go-round has radius 2.40 m and moment of inertia 2100 kg⋅m2 about a vertical axle through its center, and it

turns with negligible friction.
(a) A child applies an 18.0 N force tangentially to the edge of the merry-go-round for 15.0 s. If the merry-go-round is initially at rest, what is its angular speed after this 15.0 s interval?
(b) How much work did the child do on the merry-go-round?
(c) What is the average power supplied by the child?
Physics
1 answer:
daser333 [38]2 years ago
7 0

Answer:

a) 0.31 rad/s

b) 100 J

c) 6.67 W

Explanation:

(a) the force would generate a torque of:

T = FR = 18 * 2.4 = 43.2 Nm

According to Newton 2nd law, the angular acceleration would be

\alpha = \frac{T}{I} = \frac{43.2}{2100} = 0.021 rad/s^2

It starts from rest, then after 15s it would achieve a speed of

\omega = \alpha t = 0.021 * 15 = 0.31 rad/s

(b) The distance angle swept by it is:

\theta = \frac{\alpha t^2}{2} = \frac{0.021 * 15^2}{2} = 2.314 rad

Hence the work by the child

W = T\theta = 43.2 *2.314  \approx 100 J

c) Average power to work per time unit

P = \frac{W}{t} = \frac{100}{15} = 6.67 W

You might be interested in
Can someone help me for this question?​
LUCKY_DIMON [66]

Answer:

A, 0.050 Hz

Explanation:

1) Frequency = speed divided by wavelength

time is 2* 60 = 120 seconds

distance = 6 wave lengths

speed = distance divided by time

speed = 6 wave lengths divided by 120

Hope this helps!

4 0
2 years ago
Linh builds a circuit from the diagram shown. Which bulb could Linh remove from the circuit to make all of the other bulbs stop
LenKa [72]

Answer:

4

Explanation:

In order for the current to continue flowing through the circuit (and for the bulbs to continue shining), there must be a closed path containing the battery where current can flow. Let's see the effect of removing each bulb on the circuit:

- 1: when removing bulb 1 only, the current can still flow through the path battery-bulb 3- bulb 4

- 2: when removing bulb 2 only, the current can still flow through the path battery-bulb 3- bulb 4

- 3: when removing bulb 3 only, the current can still flow through the path battery-bulb 1-bulb 2- bulb 4

- 4: when removing bulb 4 only, the current can no longer flow. In fact, there is no closed path that contains the battery now, so the current will not flow and all the bulbs will stop shining.

4 0
3 years ago
Read 2 more answers
Calculate the wavelength of violet light with a frequency of 750×10 to the 12
MaRussiya [10]
Wavelength of any wave = (speed) / (frequency)

Speed of light = 300,000,000 m/sec

Wavelength = 3 x 10 to the 8 / 750 x 10 to the 12 = 4 x 10 to the -7 or 400 nanometers.
3 0
2 years ago
Read 2 more answers
Without completing the calculations, determine what the new volume will be in the problem below. Also, explain how you were able
Talja [164]
Boyles law

Pressure and volume are inversely proportional as the new variable changes from the known.

Double the pressure equals 1/2 of original volume, assuming temperature remains the same.

So 40.0 mL is the new volume as it is compressed.
7 0
3 years ago
A boat having stones floats in water. If stones are unloaded in water, what will happen to the level of water?​
Pani-rosa [81]

Explanation:

If the stones are unloaded from the boat, the weight of the boat will decrease. Therefore, the volume of the water displaced by the boat will also decrease. Due to this, the volume of the boat immersed in the water decreases. Hence, the level of the water around the boat will decrease.

5 0
2 years ago
Other questions:
  • a 0.45 kg soccer ball changes its velocity by 20.0 m/s due to a force applied to it in 0.10 seconds. what force was necessary fo
    6·1 answer
  • Which of the following is/are the best example(s) of elastic collision(s)? Explain why you chose your answer(s).
    5·1 answer
  • A ball is thrown upward in the air, and its height above the ground after t seconds is H ( t ) = 63 t − 16 t 2 feet. Find the ti
    7·1 answer
  • CAN SOMEONE HELP PLEASE
    8·1 answer
  • Who is the silentest that revised the atomic modle
    5·1 answer
  • Which of the following statements regarding heuristics and empiricism is true? A. Heuristics allows a priori theoretical concep
    8·1 answer
  • A baseball is hit high and far. Which of the following statements is true? At the highest point,
    6·1 answer
  • A sports car accelerates at a constant rate from rest to a speed of 90 km/hr in 8 s. What is its acceleration?
    9·1 answer
  • An objec with a mass of 7 kg accelerates 5m/s2 when an unknown force is applied to it.what is the magnitude of the unknown force
    13·1 answer
  • If two automobiles have the same acceleration, do they have the same<br> velocity? Why or why not?
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!