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
mart [117]
3 years ago
9

Q1: A runner is jogging in a straight line at a steady vr= 6.8 km/hr. When the runner is L= 2.4 km from the finish line, a bird

begins flying straight from the runner to the finish line at vb= 13.6 km/hr (2 times as fast as the runner). When the bird reaches the finish line, it turns around and flies directly back to the runner. What cumulative distance does the bird travel? Even though the bird is a dodo, assume that it occupies only one point in space (a “zero” length bird), travels in a straight line, and that it can turn without loss of speed. Answer in units of km. Q2: After this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. The bird repeats the back and forth trips until the runner reaches the finish line. How far does the bird travel from the beginning (including the distance traveled to the first encounter)? Answer in units of km.
Physics
1 answer:
serious [3.7K]3 years ago
6 0

Answer:

Q1: 3.2km

Q2: 4.8K

Explanation:

Q1:

So db is the distance of bird, and dr is the distance of runner

db = 2vr  and the distance of bird is going to be 2 times greater than the runner.

formulas: db = 2vr & db = 2dr

  1. db = 2dr
  2. L + (L - x) = 2x
  3. 2L - x = 2x
  4. 2L = 3x
  5. x = \frac{2}{3}L

Insert it in x = \frac{2}{3}L

\frac{2}{3}(2.4km) = 1.6km

Now we use formula db = 2dr

  1. db = 2L - x
  2. db = 2(2.4km) - 1.6km
  3. <u>db = 3.2km</u>

Q2:

Formulas: Vr = L /Δt & Vb = db/Δt

  1. Vr = L/ Δt ⇒ Δt = \frac{L}{Vr}
  2. \frac{2.4km}{6.8km/hr}
  3. \frac{6}{17}hr

(Km cancel each other)

  1. Vb = db/Δt ⇒ db = VbΔt
  2. 13.6km/hr(\frac{6}{17}hr )
  3. <u>4.8km</u>

(hr cancel each other)

Hope it helps you :)

You might be interested in
Which statement is false?
Mkey [24]

Answer:

Once you reach adulthood, you will not experience peer pressure.

Explanation:

We tend to believe that self-control comes from within, but many of our attitudes depend as much on friends and family as on ourselves. That's because at any stage of our life (even the adult stage) our friends and our family have the power to influence us, sometimes that influence is good and sometimes bad, it's up to us to reason about them.

The people around us have the power to make us fat, consume more alcohol, worry less about the environment and expose ourselves to the sun without proper protection, among many other things.

It is not simply about peer pressure, where you deliberately act in a certain way to suit the group. It is, in fact, largely an unconscious attitude. Without your awareness, your brain is constantly picking up cues from people around you to dictate your behavior. And the consequences can be serious.

3 0
3 years ago
Read 2 more answers
A block is released to slide down a frictionless incline of 15∘ and then it encounters a frictional surface with a coefficient o
Elodia [21]

The block's potential energy at the top of the incline (at a height h from the horizontal surface) is equal to its kinetic energy at the bottom of the incline, so that

mgh = 1/2 mv²

where v is its speed at the bottom of the incline. It follows that

v = √(2gh)

If the incline is 20.4 m long, that means the block has a starting height of

sin(15°) = h/(20.4 m)   ⇒   h = (20.4 m) sin(15°) ≈ 5.2799 m

and so the block attains a speed of

v = √(2gh) ≈ 10.1728 m/s

The block then slides to a rest over a distance d. Kinetic friction exerts a magnitude F over this distance and performs an amount of work equal to Fd. By the work-energy theorem, this quantity is equal to the block's change in kinetic energy, so that

Fd = 0 - 1/2 mv²   ⇒   d = (-1293.58 J)/F

By Newton's second law, the net vertical force on the block as it slides is

∑ F [vertical] = n - mg = 0

where n is the magnitude of the normal force, so that

n = mg = (25 kg) g = 245 N

and thus the magnitude of friction is

F = -0.16 (245 N) = -39.2 N

(negative since it opposes the block's motion)

Then the block slides a distance of

d = (-1293.58 J) / (-39.2 N) ≈ 32.9994 m ≈ 33 m

5 0
2 years ago
In 5 meters, a person running at 0.8 m/s accelerates at 1.6 m/s2. How fast 16 points
frutty [35]

They were going at a velocity 4.07m/s

<u>Explanation:</u>

Distance s =5 m

initial velocity u= 0.8 m/s

Acceleration a =1.6m/s2

We have to calculate the velocity with which they were going afterwards i.e final velocity.

Use the equation of motion

v^2=u^2+2as\\=0.8^2+2\times 1.6\times 5\\=16.64\\v=4.07 m/s

They were going with a velocity 4.07 m/s afterwards.

5 0
3 years ago
The convection zone is the outer most layer of the suns blank hot gases rise and then blank hear the loops form by singing cool
lora16 [44]

Answer:

Explanation:

The sun is made up of 6 parts. Namely:

  1. The core
  2. The radiation zone
  3. The convection zone
  4. The photosphere
  5. The chromosphere and
  6. The corona

The convection area is just above the radiation zone. As materials from the suns core are heated, they rise above the radiation zone towards the EDGE of the convection area then sinks back again into the radiative zone for more heat.

The radiative zone is 12.6 million Fahrenheit hot and is just above the core.

The core of the son is not solid but plasma whose motion is like gas. Its temperature stands at 48 million Fahrenheit

Cheers

5 0
3 years ago
A car of weight 300N moved through a distance of 10m when pushed by 3 students
Sati [7]

The work done by the three students is 3,000 J.

The energy transferred in the process is 3,000 J.

<h3>What is work done?</h3>
  • Work done is the product of force and distance moved by the object.

W = Fd

The work done by the three students is calculated as follows;

W = 300 x 10

W = 3,000 J

<h3>What is energy transfer?</h3>
  • This is means by which energy is converted from one form to another.

The energy transferred in the process is determined by work energy theorem.

E = W

E = 3,000 J

Learn more about work-energy theorem here: brainly.com/question/22236101

3 0
2 years ago
Other questions:
  • ​what characteristic of uranus makes it stand out from all the other jovian planets?
    10·2 answers
  • Which has more thermal energy, a 5-kg bowling all that has been resting on a hot driveway for 4 hours on a 350C day, or the same
    6·2 answers
  • The transfer of heat is through direct contact of particles is called
    13·1 answer
  • A 2kg box is pushed along a flat frictionless surface with an applied force of 53.91newton j+19.62 j were j is horizontal and j
    5·1 answer
  • Which vocabulary term is survival of the fittest
    7·1 answer
  • Can someone please help me!
    5·1 answer
  • Lightning bolts can carry currents up to approximately 20 kA. We can model such a current as the equivalent of a very long, stra
    8·1 answer
  • How does the temperature of water affect the speed of the sound waves?
    15·1 answer
  • Calculate ine gravitational potential energy of the ball using pe=m×g×h.(use g=9.8 n/kg)
    15·1 answer
  • An element is highly conductive, highly reactive, soft, and lustrous. The element most likely belongs to which group?(1 point)
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!