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
Ber [7]
1 year ago
9

A descending elevator of mass 1,000 kg is uniformly decelerated to rest over a distance of 8 m by a cable in which the tension i

s 11,000 N. The speed v_1 of the elevator at the beginning of the 8 m descent is most nearly (A)4 m/s (B) 10 m/s (C) 13 m/s (D) 16 m/s E) 21 m/s
Physics
1 answer:
Stolb23 [73]1 year ago
8 0

The speed  V_{i} of the elevator at the beginning of the 8 m descent is nearly 4 m/s. Hence, option A is the correct answer.

We are given that-

the mass of the elevator (m) = 1000 kg ;

the distance the elevator decelerated to be y = 8m ;

the tension is T = 11000 N;

let us determine the acceleration 'a' by using Newton's second law of motion.

∑Fy = ma

W - T = ma

(1000kg x 9.8 m/s² ) - 11000N = 1000 kg x a

9800 - 11000 = 1000

a = - 1.2 m/s²

Using the equation of kinematics to determine the initial velocity.

V_{f} ² = V_{i}² + 2ay

V_{i} = √ ( 2 x 1.2m/s² x 8 m )

V_{i} = √19.2 m²/s²

V_{i} = 4.38 m/s   ≈ 4 m/s

Hence, the initial velocity of the elevator is 4m/s.

Read more about the Equation of kinematics:

brainly.com/question/12351668

#SPJ4

You might be interested in
A boy is pedaling his bicycle at a velocity of 0.20km/ minute . How far will he travel in 2.5 hours
fredd [130]
30km. 24 the first two hours and 6 the half hour
4 0
3 years ago
Read 2 more answers
A person of 70 kg standing on an un-deformable horizontal surface. She bends her knees and jumps up from rest, achieving a launc
eduard

Answer:

1190 N

Explanation:

Force: This can be defined as the product of mass and velocity. The unit of force is Newton(N).

From the question,

F = ma................. Equation 1

Where F = average force, m = mass, a = acceleration.

But,

a = (v-u)/t................ Equation 2

Where v = final velocity, u = initial velocity, t = time.

Substitute equation 2 into equation 1

F = m(v-u)/t.............. Equation 3

Given: m = 70 kg, v = 1.7 m/s, u = 0 m/s (from rest), t = 0.1 s.

Substitute into equation 3

F = 70(1.7-0)/0.1

F = 1190 N.

3 0
3 years ago
A object travels at constant negative acceleration. What does the graph of the object's velocity as a fun
melomori [17]
Constant = straight line
“Travels at constant negative acc.”
Which is negative slope

Solution: B. Straight line w/ neg. slope
7 0
2 years ago
Does research lessen its value for its being cyclical? Enumerate Two Possible advantages of a cyclical research
Tanya [424]

Answer:

Research usually is a cyclical process because it starts with a problem and ends with a problem.

This is bad or lessens the value of the research?

No, because there are problems that in nature are cyclical, (for example the related ones to action research).

And it also may be a good thing, solving one "problem" leads to another problem, but in the process of solving the first one we may win a lot of knowledge, and the same happens with the next one, and so on.

Two possible advantages of cyclical research are:

Knowing beforehand that the research will be cyclical, will allow us to estimate better the amount of time and money needed because we already know (more or less) where to aim.

It also may lead to a better end product, as we already know that we must focus in solving one thing and then we can focus in the next one.

Another possible advantage may be that we know that after the work, there will be a new thing to research, and it is fun, so if you are curious enough this may be a good thing (especially in scientific areas, physics, chemistry, etc).

7 0
3 years ago
Astronomers can now report that active star formation was going on at a time when the universe was only 20% as old as it is toda
disa [49]

Answer:

First, as you may know, the light travels at a given velocity.

In vaccum, this velocity is c = 3x10^8 m/s.

And we know that:

distance = velocity*time

Now, if some object (like a star ) is really far away, the light that comes from that star may take years to reach the Earth.

This means that the images that the astronomers see today, actually happened years and years ago (So the night sky is like a picture of the "past" of the universe)

Also, for example, if an astronomer sees some particular thing, he can apply a model (a "simplification" of some phenomena that is used to simplify it an explain it) and with the model, the scientist can infer the information of the given thing some time before it was seen.

8 0
3 years ago
Other questions:
  • Explain what it means when we describe an ecosystem as being in equilibrium
    6·2 answers
  • In lemonade, sugar is ____ and water is the _____ .
    8·1 answer
  • PLZ HELP ME 50 POINTS AND BRAINLEIST Which processes do you suppose are responsible for the formation of hail during a thunderst
    11·1 answer
  • 1.<br> Distinguish between amplitude and frequency and give an example.
    5·1 answer
  • Gases have two specific heat values .....?
    9·1 answer
  • A car accelerates uniformly from rest at 2.2 m / s^2 for 3.0 s.Calculate the speed of the car at time t = 3.0 s
    5·1 answer
  • URGENT PHYSIC PLEASE.
    13·1 answer
  • A small difference between means may not be statistically significant, but it could reach statistical significance with a large
    5·1 answer
  • A flea stands on the end of a 1.0 cm long
    7·1 answer
  • If a Ferrari, with an initial velocity of 10 m/s, accelerates at a rate of 50 m/s 2 for 3 seconds, what will its final velocity
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!