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
Nina [5.8K]
3 years ago
9

A 20-Kg child is on a swing attached to 3.0 m-long chains. The child swings back and forth, swinging out to a 60-degree angle. (

This is the angle that the chains make with the vertical.) What is the childs maximum speed on the swing
Physics
1 answer:
kvv77 [185]3 years ago
6 0

Answer:

 v = 29.4 m / s

Explanation:

For this exercise we can use the conservation of mechanical energy

Lowest starting point.

          Em₀ = K = ½ m v²

final point. Higher

          Em_{f} = U = m g h

Let's use trigonometry to lock her up

          cos 60 = y / L

          y = L cos 60

Height is the initial length minus the length at the maximum angle

           h = L - L cos 60

           h = L (1- cos 60)

energy is conserved

         Em₀ = Em_{f}

          ½ m v² = mgL (1 - cos 60)

         v = 2g L (1- cos 60)

 

let's calculate

          v² = 2 9.8 3.0 (1- cos 60)

          v = 29.4 m / s

You might be interested in
If you were on a ship at sea, and a tsunami passed under your ship, what would probably be your reaction? explain.
swat32
<span>Extremely powerful single waves have no effect on ships at sea since the depth of water allows the energy to be distributed over hundreds and thousands of feet. In deep water, the bigger the wave, the faster it moves and the slower the surface changes height. As the wave gets into shallow waters, it slows down and can start to pile up to large heights.</span>
6 0
2 years ago
4. Identify Problems A student is describing a longitudinal wave in his notebook. He
andrew11 [14]

Answer:

 "The distance between crests is 3 cm." 

Explanation:

If he writes down "The distance between crests is 3 cm." 

That means he is describing the wavelength of a wave and not longitudinal wave. He ought to write something about " direction "

Longitudinal waves are waves in which the displacement of the medium is in the same direction as, or parallel to, the direction of propagation of the wave. While

Wavelength is the distance between the two successfully Crest or trough

3 0
3 years ago
A disc is thrown through the air for 1.5 min with a power output of 12.5 W. How much work is done when throwing the disc?
klasskru [66]

Answer:

work = 1125 [J]

Explanation:

To solve this problem we must remember the definition of power, which is defined as the relationship between work and time. The power can be calculated using the following equation:

Power = work/time

Power = 12.5 [w]

work = joules [J]

time = 1.5 [min] = 90 [s]

work = 12.5*90

work = 1125 [J]

7 0
3 years ago
"Videos of hoverboard riders who were injured when they fell while operating their hoverboards at a low speeds "went viral" over
bagirrra123 [75]

Answer:

The answer is "No, Hoverboards are risky, and riders are in danger of falling".

Explanation:

It's also known as a self-balanced scooter, it handheld electrical devices traveling on two wheels are hoverboards. It dominated the industry around 2015 and since then has become more and more successful. A rider is balanced on a frame between these wheels, driven by battery-powered lithium-ion batteries.

8 0
2 years ago
What is the period of a simple pendulum 47 cm long (a) on the Earth, and ( b) when it is in a freely falling elevator?
Liula [17]

Answer:

a)1.37 s

b)∞ ( Infinite)

Explanation:

Given that

L= 47 cm              ( 1 m =100 cm)

L= 0.47 m

a)

On the earth :

Acceleration due to gravity = g

We know that time period of the simple pendulum given as

T=2\pi\sqrt{ \dfrac{L}{g_{{eff}}}

Here

g_{eff}= g

Now by putting the values

T=2\pi \times\sqrt{ \dfrac{0.47}{9.81}}

T=1.37 s

b)

Free falling elevator :

When elevator is falling freely then

g_{eff}= 0            ( This is case of weightless motion)

Therefore

T=2\pi\sqrt{ \dfrac{L}{0}

T=∞  (Infinite)

6 0
3 years ago
Other questions:
  • What are some common forces that make it difficult for humans to
    10·1 answer
  • Explain why the cyclist must be fed in order to continue to pedal? answer fast please​
    7·1 answer
  • A long wire carrying a 5.8 A current perpendicular to the xy-plane intersects the x-axis at x=−2.3cm. A second, parallel wire ca
    6·1 answer
  • Velocity is the slope of the acceleration vs. time graph.<br> A.) True<br> B.)False<br> (apex)
    14·2 answers
  • In our usual coordinate system( +x to the right, +y up (away from the center of the Earth), +z out of the page toward you), what
    15·1 answer
  • What is a specific heat capacity?
    10·2 answers
  • What is the effect of divorce on females?​
    8·2 answers
  • What is the velocity of a 1200 kg boat with a kinetic energy of 160,000 J​
    5·1 answer
  • PLEASE HELP ME! IM TIMED
    13·1 answer
  • What principle do Tesla coils use to generate electricity?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!