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
Vera_Pavlovna [14]
4 years ago
12

Which of the following is true about a planet orbiting a star in uniform circular motion? A. The direction of the velocity vecto

r is always changing. B. The velocity of the planet is constant. C. The speed of the planet is always changing. D. The acceleration vector of the planet points directly away from the star.
Physics
2 answers:
Sunny_sXe [5.5K]4 years ago
6 0

Answer;

A.The direction of the velocity vector is always changing.

Explanation;

-A circular orbit of a planet around a star is an example of uniform circular motion (its speed remains constant).

--When a planet has just the right speed (for a given radius of orbit), then it will travel in circular motion with a constant speed. This is called uniform circular motion. Note that the velocity vector changes direction although the speed is constant. This means that there must be a net force on the planet.

Luda [366]4 years ago
4 0
<span>As it is uniform circular motion therefore speed is constant. Therefore we can rule out option B. Also in circular motion the direction of velocity vector changes therefore velocity can't be constant. Therefore option B is incorrect as well. Also centripetal acceleration is always towards the center so option D is wrong as well. That implies option A is correct.</span>
You might be interested in
Dina has a mass of 50 kilograms and is waiting at the top of a ski slope that’s 5.0 meters high.
Over [174]
All of Dina's potential energy Ep is converted into kinetic energy Ek so Ep=Ek, where Ep=m*g*h and Ek=(1/2)*m*v². m is the mass of Dina, h is the height of ski slope, g=9.8 m/s² and v is the maximal velocity. 

So we solve for v:

m*g*h=(1/2)*m*v², masses cancel out,

g*h=(1/2)*v², we multiply by 2,

2*g*h=v² and take the square root to get v

√(2*g*h)=v, we plug in the numbers and get:

v=9.9 m/s. 

So Dina's maximum velocity on the bottom of the ski slope is v=9.9 m/s.
8 0
3 years ago
Read 2 more answers
One charge is decreased to one-third of its original value, and a second charge is decreased to one-half of its original value.
Elanso [62]

I just had this question on my test, the answer is C.

8 0
4 years ago
Read 2 more answers
A pizza delivery driver must make three stops on her route. She will first leave the restaurant and travel 4 km due north to the
topjm [15]
<h2>5.3 km</h2>

Explanation:

       This question involves continuous displacement in various directions. When it becomes difficult to imagine, vector analysis becomes handy.

       Let us denote each of the individual displacements by a vector. Consider the unit vectors \vec{i}\textrm{ and }\vec{j} as the unit vectors in the direction of East and North respectively.

       By simple calculations, we can derive the unit vectors \vec{j},\frac{-\vec{i}-\vec{j}}{2}\textrm{ and }\frac{-\frac{1}{2}\vec{i}+\frac{\sqrt{3}}{2}\vec{j}}{2} in the directions North, 45^{o} South of West and 60^{o} North of West respectively.

       So Total displacement vector = Sum of individual displacement vectors.

       Displacement vector = 4(\vec{j})+6(\frac{-\vec{i}-\vec{j}}{2})+5(\frac{-\frac{1}{2}\vec{i}+\frac{\sqrt{3}}{2}\vec{j}}{2})=-4.25\vec{i}+3.165\vec{j}

       Magnitude of Displacement = |-4.25\vec{i}+3.165\vec{j}|=5.3km

∴ Total displacement = 5.3km

4 0
3 years ago
Please help ASAP. How is heat related to work?
earnstyle [38]
Energy is the ability to do work so I would say that thermal or heat energy is a type of work. Don’t know if this will work but that’s what I would put.
7 0
4 years ago
The gravitational pull of the sun on Earth keeps Earth orbiting around the sun. Which statement is correct about the force that
Furkat [3]

Answer:

Earth pulls the sun towards itself with a force equal to the ratio of the mass of the sun to the mass of Earth

5 0
3 years ago
Other questions:
  • __________ is/are formed between two air masses that have different temperatures. (4 points) A: Wind B:The jet stream C:Clouds D
    8·2 answers
  • The speed of sound in air is about 340m/s. What is the wavelength of sound waves produced by a guitar string vibrating at 490Hz?
    13·1 answer
  • What is floatation?​
    15·2 answers
  • Why do all objects hit with the same velocity (ignoring air resistance) if dropped from the same height?
    10·2 answers
  • Is Gasoline for you car a clean source of energy?
    8·1 answer
  • The size of the electrical potential is measured in
    9·1 answer
  • The current through one resistor in a parallel resistor circuit is always (need help ASAP)
    6·1 answer
  • What happens to energy and matter when a wave moves through space?
    6·1 answer
  • A negative charge of 4.0 x 10 C and a positive charge of 7.0 x 10 C are separated by 0.15 m. What is
    6·1 answer
  • Diffrence between UFP&amp;LFP​
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!