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
crimeas [40]
3 years ago
14

An elevator cable breaks when a 925-kg elevator is 28.5 m above the top of a huge spring Ak = 8.00 * 104 N????mB at the bottom o

f the shaft. Calculate (a) the work done by gravity on the elevator before it hits the spring; (b) the speed of the elevator just before striking the spring; (c) the amount the spring compresses (note that here work is done by both the spring and gravity).
Physics
2 answers:
Soloha48 [4]3 years ago
8 0

Answer:

a) The work done by gravity on the elevator is 258352.5 J

b) The speed of the elevator just before striking the spring is 23.63 m/s

c) The amount the spring compresses is 2.7 m

Explanation:

a) The work is equal to:

W=Fdcos\theta \\W=mgdcos\theta

Where

m = 925 kg

g = 9.8 m/s²

d = 28.5 m

θ = 0°

Replacing:

W=925*9.8*28.5*cos0=258352.5J

b) The work done by gravity on the elevator is equal to the change of kinetic energy:

W = ΔEk

W=\frac{1}{2} mv^{2} -0

The velocity is:

v=\sqrt{\frac{2W}{m} } =\sqrt{\frac{2*258352.5}{925} } =23.63m/s

c) The total work is equal to the sum to of the change of kinetic energy and the spring:

W_{g} +W_{spring} =0\\\frac{k}{2} x^{2} -(mg)x-mgd=0\\x=\frac{mg+-\sqrt{m^{2} g^{2}+2kmgd } }{k}

Replacing:

x=\frac{925*9.8+-\sqrt{925^{2}*9.8^{2}+(2*8x10^{4}*925*9.8*28.5)   } }{8x10^{4} } =2.7m

rosijanka [135]3 years ago
3 0

Answer:

a) = 258352.5J

b) = 23.63 m/s

c) = 1.8m

Explanation:

Data;

Mass = 925kg

Distance (s) = 28.5m

Force constant (k) = 8.0*10⁴ N/m

g = 9.8 m/s²

a) = work = force * distance

But force = mass * acceleration

Force = 925 * 9.8 = 9065N

Work = F * s = 9065 * 28.5 = 258352.5J

b) acceleration (a) = (v² - u²) / 2s

a = v² / 2s

v² = a * 2s

v² = 9.8 * (2 * 28.5)

v² = 9.8 * 57

v² = 558.6

v = √(558.6)

V = 23.63 m/s

C). The work stops when the work done to raise the spring equals the work done to stop it by the spring

W = ½kx²

258352.5 = ½ * 8.0*10⁴ * x²

(2 * 258352.5) = 8.0*10⁴x²

516705 = 8.0*10⁴x²

X² = 516705 / 8.0*10⁴

X² = 6.46

X = √(6.46)

X = 2.54m

The compression was about 2.54m

You might be interested in
A car travels along the motorway at a steady 70 m.p.h. How far will it travel in half an hour?
Sergeu [11.5K]

If a car is travelling 70 m.p.h that means it is travelling 70 miles PER HOUR and since we want to know half an hour we can do

70mph divided by 2 =35m.p half hour so the car is travelling 35miles in half an hour

8 0
3 years ago
Read 2 more answers
A slit of width 2.0 μm is used in a single slit experiment with light of wavelength 650 nm. If the intensity at the central maxi
Valentin [98]

Answer:

The intensity at 10° from the center is 3.06 × 10⁻⁴I₀

Explanation:

The intensity of light I = I₀(sinα/α)² where α = πasinθ/λ

I₀ = maximum intensity of light

a = slit width = 2.0 μm = 2.0 × 10⁻⁶ m

θ = angle at intensity point = 10°

λ = wavelength of light = 650 nm = 650 × 10⁻⁹ m

α = πasinθ/λ

= π(2.0 × 10⁻⁶ m)sin10°/650 × 10⁻⁹ m

= 1.0911/650 × 10³

= 0.001679 × 10³

= 1.679

Now, the intensity I is

I = I₀(sinα/α)²

= I₀(sin1.679/1.679)²

= I₀(0.0293/1.679)²

= 0.0175²I₀

= 0.0003063I₀

= 3.06 × 10⁻⁴I₀

So, the intensity at 10° from the center is 3.06 × 10⁻⁴I₀

5 0
3 years ago
Which of the folltrue or false: the ratio of heat exchange in conduction is independent of exposure time.owing techniques uses e
Sliva [168]

True conditions

Efficiency of Heat Exchanger are as below:

the heat exchange process between two fluids with different temperatures using solid walls occurs in various engineering applications. The tool to achieve this exchange is a heat exchanger. Some applications like air conditioning, power generation, waste heat recovery, and chemical processing use this device.

The basis of the work of a heat exchanger is that the hot fluid enters the heat exchanger at temperature T1 and its heat capacity is Chot. Also, the cold fluid with the heat capacity of Ccold enters temperature t1; in the meantime, the hot fluid loses its heat, and its temperature drops to T2. It delivers heat to the cold fluid to increase its temperature to t2 and leave the heat exchanger at this temperature.

To learn more about Heat Exchanger

brainly.com/question/22595817

#SPJ4

6 0
2 years ago
if the separation distance between the moon and the planet is increased by a factor of 4 then the force gravitational is
erastova [34]

Answer:

Fg = (G * m1 * m2) / r^2

The gravitational force is Fg/16

Explanation:

Fg = (G * m1 * m2) / (4r)^2

Fg = (G * m1 * m2) / 16r

Therefore,

Fg / 16

8 0
3 years ago
Read 2 more answers
Interactive Solution 9.1 presents a model for solving this problem. The wheel of a car has a radius of 0.300 m. The engine of th
Murrr4er [49]

Answer:

740 N

Explanation:

We are given that

Radius,r=0.3 m

Torque,\tau=222 Nm

We have to find the magnitude of the static frictional force.

According to question

Torque by engine=Torque by static friction

222=f\times r

f=\frac{222}{r}

f=\frac{222}{0.3}

f=740 N

Hence, the magnitude of static frictional force=740 N

8 0
3 years ago
Other questions:
  • The electrons that are gained or lost in an ionic bond are called...?
    10·1 answer
  • A freight car moves along a frictionless level railroad track at constant speed. The freight car is open on the top. A large loa
    10·1 answer
  • Please help: I don't know how to do these problems
    12·1 answer
  • A persons height will be the same on jupiter and earth. A persons weight will be greater on jupiter than on earth. True or false
    5·1 answer
  • Matt forgot to put the fabric softener in the wash. As his socks tumbled in the dryer, they became charged. If a small piece of
    10·1 answer
  • Any object that just fits into your visual field has this angular size. Do all objects that you see this this angular size have
    13·1 answer
  • How many ways or features that allow us to know if something is living or non living?
    11·1 answer
  • It takes 52,000 Joules to heat a cup of coffee to boiling from room temperature. How long a piece of 20 cm wide Aluminum foil wo
    15·1 answer
  • A person on a daily diet of 2,500 calories should get no_more than <br> calories from fat each day.
    6·2 answers
  • It is made up of small particles
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!