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
nordsb [41]
3 years ago
9

A 34-kg child on an 18-kg swing set swings back and forth through small angles. If the length of the very light supporting cable

s for the swing is 4.9 m, how long does it take for each complete back-and-forth swing? Assume that the child and swing set are very small compared to the length of the cables.
Physics
1 answer:
kompoz [17]3 years ago
5 0

Answer:

4.44s

Explanation:

A 34-kg child on an 18-kg swing set swings back and forth through small angles. If the length of the very light supporting cables for the swing is 4.9 m, how long does it take for each complete back-and-forth swing? Assume that the child and swing set are very small compared to the length of the cables

since the mass of the child and that of the swing is negligible, the masses wont be involved in the calculation

T=2π√L/g

g=acceleration due to gravity which is 9.81m/s2

the length of the supporting cable is 4.9m

T the period

period is the time required to make a complete oscillation

T=2*π√4.9/9.81

T=2*π*0.706

T=4.44s

4.44s

You might be interested in
A spaceship moves radially away from Earth with acceleration 29.4 m/s 2 (about 3g). How much time does it take for sodium street
Gemiola [76]

Answer:

doppler shift's formula for source and receiver moving away from each other:

<em>λ'=λ°√(1+β/1-β)</em>

Explanation:

acceleration of spaceship=α=29.4m/s²

wavelength of sodium lamp=λ°=589nm

as the spaceship is moving away from earth so wavelength of earth should increase w.r.t increasing speed until it vanishes at λ'=700nm

using doppler shift's formula:

<em>λ'=λ°√(1+β/1-β)</em>

putting the values:

700nm=589nm√(1+β/1-β)

after simplifying:

<em>β=0.17</em>

by this we can say that speed at that time is: v=0.17c

to calculate velocity at an acceleration of a=29.4m/s²

we suppose that spaceship started from rest so,

<em>v=v₀+at</em>

where v₀=0

so<em> v=at</em>

as we want to calculate t so:-

<em>t=v/a</em>                                                v=0.17c      ,c=3x10⁸           ,a=29.4m/s²

putting values:

=0.17(3x10⁸m/s)/29.4m/s²

<em>t=1.73x10⁶</em>

7 0
3 years ago
Arigid body must rotate about an axis in order for it to have angular momentum about that axis. True False
kompoz [17]

Answer:

False

Explanation:

Let's consider the definition of the angular momentum,

\vec{L} = I \vec{\omega}

where I = \int\limits_m r^2 dm = \lim_{n \to \infty} \sum\limits_{i=1}^n m_i r_i^2 is the moment of inertia for a rigid body. Now, this moment of inertia could change if we change the axis of rotation, because "r" is defined as the distance between the puntual mass and the nearest point on the axis of rotation, but still it's going to have some value. On the other hand,

\vec{\omega} = \frac{\vec{r} \times \vec{v}}{r^2} so \vec{\omega} \neq 0 unless \vec{r} ║  \vec{v}.

In conclusion, a rigid body could rotate about certain axis, generating an angular momentum, but if you choose another axis, there could be some parts of the rigid body rotating around the new axis, especially if there is a projection of the old axis in the new one.

7 0
3 years ago
A planet orbits a sun in a clockwise elliptical orbit as shown in the diagram below
STatiana [176]

Answer:

Greatest gravitational energy is at "C".

The planet has to do work "against" the field to get to "C".

Also, if m v R (angular momentum) is constant then as R increases v must decrease for this term to be constant and KE = 1/2 M v^2  must decrease also to get to point C.

3 0
3 years ago
A dairy farmer notices that a circular water trough near the barn has become rusty and now has a hole near the base. The hole is
Crazy boy [7]

Answer:

v=1.93m/s

Explanation:

From the concept of fluids mechanics we know that if a tank has a hole at the bottom, the equation that we need to use is:

v=\sqrt{2gh}

Since we know gravity and its hight

v=\sqrt{2*(9.81m/s^{2})(0.19m) }=1.93m/s

5 0
3 years ago
Which of the following best describes how galaxies exist in the universe?
anzhelika [568]
I think the correct answer from the choices listed above is option D. Galaxies exist in the universe as they  form clusters that are light-years away from other clusters. Other choices are really far away from the truth. Hope this answers the question. Have a nice day.
4 0
3 years ago
Read 2 more answers
Other questions:
  • Choose all the answers that apply. Which of the following forces require physical contact? tension, air resistance, friction, ma
    15·1 answer
  • NEED HELP RIGHT NOW PLSSSS!!
    8·1 answer
  • Light of wavelength 608.0 nm is incident on a narrow slit. The diffraction pattern is viewed on a screen 88.5 cm from the slit.
    9·1 answer
  • What is the word for the definition of an electron in the highest occupied energy level of an atom
    6·1 answer
  • When is zero considered significant​
    12·2 answers
  • “Is there a relationship between mass and gravity of a planet?” If there is a relationship, (such as- as the mass gets bigger th
    5·1 answer
  • Tammy jogged 350 meters at a velocity of 7 m/s. How long did it take her to jog this distance?
    13·2 answers
  • Which atmospheric layer prevents meteoroids from reaching earth’s surface
    7·1 answer
  • N which order did the events forming our solar system occur?
    12·2 answers
  • Calculate the frequency of the wave shown below.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!