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
Sphinxa [80]
3 years ago
15

An airplane engine starts from rest; and 2 seconds later, it is rotating with an angular speed of 300 rev/min. if the angular ac

celeration is constant, how many revolutions does the propeller undergo during this time?
Physics
1 answer:
elena-s [515]3 years ago
3 0

First of all, we need to convert the angular speed from rev/min into rev/s:

\omega_f=300 rev/min=5 rev/s

The angular acceleration is the variation of angular speed divided by the time:

\alpha=\frac{\omega_f-\omega_i}{t}=\frac{5 rev/s-0}{2 s}=2.5 rev/s^2

And this is constant, so we can use the following equation to calculate the angle through which the engine has rotated:

\theta(t)=\frac{1}{2}\alpha t^2 =\frac{1}{2}(2.5 rev/s^2)(2 s)^2=5 rev

so, 5 revolutions.

You might be interested in
A small boat coasts at constant speed under a bridge. A heavy sack of sand is dropped from the bridge onto the boat. The speed o
Tju [1.3M]

Answer:

d. decreases

Explanation:

The law of conservation of momentum tells us that the sum of momenta before the collision is equal to the sum of momenta after the collision. The bag has no momentum as it falls onto the boat because its velocity is zero in the horizontal direction. But after it hits the boat, it's momentum increases while the momentum of the system remains the same. That means a component of the system must decrease somewhere else. And that component is the velocity, not the mass, of the boat.

7 0
3 years ago
Describe the difference between a conductor and an insulator in terms of thermal energy transfer and provide an example of each.
Nikitich [7]

The difference between conductors and insulators is because of electronic structure of atoms and molecules.

 

Anywhere we have free electrons, we have a hard conductor where free electrons help in conduction.

 

In electrolytes, charged Ions do conduction.

 

Dielectrics (or insulators) don't have free electrons current.

 

Free electrons mean, the electrons that are not related with a specific atom, they are allowed to move nearby the crystal lattice.

4 0
3 years ago
The map of the world is overlaid with the boundaries of the tectonic plates. Look at the location marked with an asterisk (*). W
Sholpan [36]
<span>C) mountains; two continental plates meet at a convergent boundary</span>
6 0
3 years ago
Bx = -1.33 m and By = 2.81 m<br> Find the magnitude of the<br> vector.
NISA [10]

Answer:

Explanation:

The formula for the magnitude of a vector is

B_{mag}=\sqrt{(-1.33)^2+(2.81)^2} and then round to the hundredths place:

3.11 m. Since we are in Q2, we can also find the direction of this vector:

tan^{-1}(\frac{2.81}{-1.33})=-64.7 but since we are in Q2, we add 180 degrees to the result, getting the angle to be 115.3

3 0
2 years ago
QUESTION 36
mel-nik [20]

Answer:

Explanation:

m = ρV = 1.03( 1000 kg/m³)(π(2² m²)(3.0 m)) = 12360π kg

m ≈ 38,830 kg

5 0
3 years ago
Other questions:
  • How do you determine if a charged comb is positively charged or negatively charged. Suppose it is positively charged, it will at
    5·1 answer
  • The radius of a sphere is increasing at a rate of 9 cm/ sec. Find the radius of the sphere when the volume and the radius of the
    11·1 answer
  • The air in a room has a pressure of 1 atm, a dry-bulb temperature of 24°C, and a wet-bulb temperature of 17°C. Using the psychro
    15·1 answer
  • You are standing on the SCALE<br> The scale is on the floor.<br> What are the forces on the SCALE?
    10·2 answers
  • A rectangular plate is supported by three cables as shown. knowing that the tension in cable ab is 408 n, determine the componen
    6·1 answer
  • a wire with mass per unit length 75 g/m runs horizontally at right angles to a uniform horizontal 0.12 T magnetic field. what am
    7·1 answer
  • Which statement about the physical properties of matter is true? (15)
    14·1 answer
  • Describe how the potential energy changes
    8·2 answers
  • Which of the following plays a major role in creating surface currents?
    10·2 answers
  • A mechanic pushes a 2.30 ✕ 103-kg car from rest to a speed of v, doing 4,800 J of work in the process. During this time, the car
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!