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
Bumek [7]
3 years ago
13

A crew on a spacecraft watches a movie that is two hours long. The spacecraft is moving at high speed through space. An Earth-ba

sed observer watching the movie screen on the spacecraft through a powerful telescope measures the duration of the movie to be _______ two hours.
Physics
1 answer:
laiz [17]3 years ago
4 0

Answer:

The duration of the movie is longer than 2 hrs.

Explanation:

Given:

The duration of the movie observed by the crew on the spacecraft is 2 hrs.

According to time-dilation formula:

t = \dfrac{t_{0}}{\sqrt{1 - \dfrac{v^{2}}{c^{2}}}}

Here, t is the required time, t_{0} is the original time, v is the velocity of the spacecraft and c is the velocity of light.

Since v, so t_{0} > t.

So the time required will be large.

You might be interested in
Which sentences describe the cyclone device?
Yakvenalex [24]

Answer:

✓ A cyclone device accumulates fine particulates from the air by making a dirty air stream flow in a spiral path inside a  cylindrical chamber.

✘ It consists of several long and narrow fabric filter bags suspended upside-down in a large  enclosure.

✓ When dirty air enters the chamber, the larger particulates strike the chamber wall and fall into a conical dust  hopper at the bottom.

✘ Fans blow dirt-filled air upward from the bottom of the enclosure, trapping dirt particles inside the  filter bags and releasing clean air from the top.

✓ The top of the chamber has an outlet that lets out cleaned air.

Basically, any of these choices that have the word "filter" are wrong. The point of the cyclone device is to separate the particles without the use of filters. You can tell the right answers based on the picture attached below.

3 0
3 years ago
Read 2 more answers
Frictional force is caused by the interaction of a body with​
zheka24 [161]

Answer:

Frictional force always acts parallel to two planes in contact with each other and in a direction opposite to that of relative motion of the two bodies. 2. Frictional forces are caused due to intermolecular interactions between the bodies.  Frictional force is more for rough surface and less for smooth surfaces.

6 0
3 years ago
Read 2 more answers
How many electrons are in the third energy level of a calcium atom
lidiya [134]
There are 8 electrons in the third energy level of Calcium atom.  
4 0
3 years ago
Read 2 more answers
A cart, which has a mass of 2.30 kg is sitting at the top of an inclined plane, which is 4.50 meters long and meets the horizont
expeople1 [14]

Answer:

a) The gravitational potential energy before the cart rolls down the incline is 24.6 J.

b) The magnitude of the force that causes the cart to roll down is 5.47 N.

c) The acceleration of the cart is 2.38 m/s²

d) It takes the cart 1.94 s to reach the bottom of the incline.

e) The velocity of the cart at the bottom of the inclined plane is 4.62 m/s.

f) The kinetic energy of the cart as it reaches the bottom of the incline is 24.6 J.

g) The work done by the gravitational force is 24.6 J.

Explanation:

Hi there!

a) The gravitational potential energy is calculated using the following equation:

EP = m · g · h

Where:

EP = gravitational potential energy.

m = mass of the object.

g = acceleration due to gravity.

h = height at which the object is located.

The height of the inclined plane can be calculated using trigonomoetry:

sin 14.0° = height / lenght

sin 14.0° = height / 4.50 m

4.50 m · sin 14.0° = height

height = 1.09 m

Then, the gravitational potential energy will be:

EP = m · g · h

EP = 2.30 kg · 9.81 m/s² · 1.09 m = 24.6 J

The gravitational potential energy before the cart rolls down the incline is 24.6 J.

b) Please, see the attached figure for a graphical description of the problem and the forces acting on the cart. The force that causes the cart to accelerate down the incline is the horizontal component of the weight (Fwx in the figure). The magnitude of this force can be obtained using trigonometry:

sin 14° = Fwx / Fw

The weight of the cart (Fw) is calculated as follows:

Fw = m · g

Fw = 2.30 kg · 9.81 m/s²

Fw = 22.6 N

Then, the x-component of the weight will be:

FW · sin 14° = Fwx

22.6 N · sin 14° = Fwx

Fwx = 5.47 N

The magnitude of the force that causes the cart to roll down is 5.47 N.

c)Using the equation of Fwx we can calculate the acceleration of the cart:

Fwx = m · a

Where "m" is the mass of the cart and "a" is the acceleration.

Fwx / m = a

5.47 N / 2.30 kg = a

a = 2.38 m/s²

The acceleration of the cart is 2.38 m/s²

d) To calculate the time it takes the cart to reach the bottom of the incline, let´s use the equation of position of the cart:

x = x0 + v0 · t + 1/2 · a · t²

Where:

x = position of the cart at time t.

x0 = initial position.

v0 = initial velocity.

a = acceleration.

t = time.

Considering the initial position as the point at which the cart starts rolling (x0 = 0) and knowing that the cart starts from rest (v0 = 0), let´s find the time it takes the cart to travel the 4.50 m of the inclined plane:

x = 1/2 · a · t²

4.50 m = 1/2 · 2.38 m/s² · t²

2 · 4.50 m / 2.38 m/s² = t²

t = 1.94 s

It takes the cart 1.94 s to reach the bottom of the incline.

e) The velocity of the cart at the bottom of the inclined plane can be obtained using the following equation:

v = v0 + a · t

v = 0 m/s + 2.38 m/s² · 1.94 s

v = 4.62 m/s

The velocity of the cart at the bottom of the inclined plane is 4.62 m/s.

f) The kinetic energy can be calculated using the following equation:

KE = 1/2 · m · v²

Where:

KE =  kinetic energy.

m = mass of the cart.

v = velocity of the cart.

KE = 1/2 · 2.30 kg · (4.62 m/s)²

KE = 24.6 J

The kinetic energy of the cart as it reaches the bottom of the incline is 24.6 J.

The gain of kinetic energy is equal to the loss of gravitational potential energy.

g) The work done by the gravitational force can be calculated using the work-energy theorem: the work done by the gravitational force is equal to the negative change in the gravitational potential energy:

W = -ΔPE

W = -(final potential energy - initial potential energy)

W = -(0 - 24.6 J)

W = 24.6 J

This can also be calculated using the definition of work:

W = Fw · d

Where "d" is the distance traveled in the direction of the force, that is the height of the inclined plane:

W = 22.6 N · 1.09 m = 24.6 J.

The work done by the gravitational force is 24.6 J.

4 0
3 years ago
A book is sliding to a stop while moving across the classroom floor
Margarita [4]

Answer:

can you please elaborate the question

Explanation:

3 0
3 years ago
Other questions:
  • Mike has been struggling to maintain a healthy weight since starting college.which of the following statements shows a positive
    7·2 answers
  • I will give Brainliest to WHoever answers truthfully!!!!!T/F net force charge and net electric force are the same thing
    6·2 answers
  • Which two statements offer evidence that the clocks energy is conserved?
    11·2 answers
  • 1. Compare pressure that fluid applies to the bottom of a glass with the pressure it applies to the sides of the glass
    9·1 answer
  • The combination of all of the forces acting on an object is called the
    12·1 answer
  • At 15°C air is transmitted <br>at 340 m/s. Express this speed<br>in Kilometers per hour.​
    7·2 answers
  • PLS HELP WILL MARK BRAINLIEST IF RIGHT NEED IMMEDIATELY PLEASEEEEE
    8·2 answers
  • What’s the doing between high and low pressure systems.
    5·1 answer
  • how does the frequency of a radio wave compare to the frequency of the vibrating electrons that produce it?
    7·1 answer
  • The same girl in number 3 (above) pushes another friend on the same skateboard.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!