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
Anastasy [175]
4 years ago
12

A spin bike has a flywheel in two parts—a 12.5 kg disk with radius 0.23 m, and a 7.0 kg ring with mass concentrated at the outer

edge of the disk. A friction pad exerts a force of 9.7 N on the outside of the disk. A cyclist is pedaling, spinning the disk at a typical 180 rpm. If she stops pedaling, how long will it take for the flywheel to come to a stop?
Physics
1 answer:
Nitella [24]4 years ago
7 0

Answer:

Explanation:

Given

mass of disk m=12.5 kg

radius of disc R=0.23 m

mass of ring m_r=7 kg

Force F=9.7 N

N=180 rpm

\omega =\frac{2\pi N}{60}

\omega =6\pi rad/s

Total moment of inertia

=Moment of inertia of Disc +Moment of Inertia of ring

=0.5\cdot 12.5\times 0.23^2+7\times 0.23^2

=13.25\times 0.23^2=0.7009 kg-m^2

Now Torque is T=F\times R=I\cdot \alpha

9.7\times 0.23=0.7\times \alpha

\alpha =3.18 rad/s^2

Now using \omega _f=\omega +\alpha t

\omega _f=0 here

0=6\pi -3.18\times t

t=\frac{6\pi }{3.18}

t=5.92 s                  

You might be interested in
Describe how the student should measure the time taken for the toy parachute to
PolarNik [594]

The time must be measured with respect to gravity. As it falls, it has free fall that is the force acting on it will be the gravity.With the distance in account, d = 1/2 gt²

t = √(2d/g)

4 0
3 years ago
1. For a reaction to occur, energy must be
amm1812

For a reaction to occur, energy must be absorbed to break chemical bonds

<u>Explanation:</u>

Reactions can be classified as chemical reaction, nuclear reaction, thermal reaction. So in these three reaction types, the nature of energy will only be varying.

But in order to execute a reaction, there should be breaking of existing bonds and then formation of new bonds. So for breaking of the bonds of reactants, energy should be absorbed from the surrounding.

Then the extra energy will be released after forming the products. Thus, the process of absorption of energy will lead to endothermic process and the process of releasing of energy will lead to exothermic reaction. So for a reaction to occur, energy must be absorbed to break the chemical bonds.

8 0
3 years ago
How much time is needed to produce 720 Joules of work if 90 watts of power is used?
Tems11 [23]

Answer:

8 seconds

Explanation:

power (P) is defined as the rate at which work is done.

power is measured in Watts (W) , when the work done is measured in Joules (J) and time in seconds

by the definition of power,

Power=\frac{work.done}{time.taken} \\ \\ time.taken=\frac{work.done}{power}\\=\frac{720J }{90W} \\ \\ =8 s

3 0
4 years ago
Aspect ratio is the ratio of images width to its height. a photograph is 17.5 cm wide by 14 cm high what is the aspect ratio in
Svet_ta [14]

Try 5:4 and see if it is correct

5 0
3 years ago
You are in charge of designing a movie stunt for a new Fast and Furious film. In this scene a stunt person has to jump from a br
blondinia [14]

Answer:

103.5 meters

Explanation:

Given that a stunt person has to jump from a bridge and land on a boat in the water 22.5 m below. The boat is cruising at a constant velocity of 48.3 m/s towards the bridge. The stunt person will jump up at 6.45 m/s as they leave the bridge.

The time the person will jump to a certain spot under the bridge can be calculated by using the formula below:

h = Ut + 1/2gt^2

since the person will fall under gravity, g = 9.8 m/s^2

Also, let assume that the person jump from rest, then, U = 0

Substitute h, U and g into the formula above

22.5 = 1/2 * 9.8 * t^2

22.5 = 4.9t^2

22.5 = 4.9t^2

t^2 = 22.5/4.9

t^2 = 4.59

t = \sqrt{4.592}

t = 2.143 seconds

From definition of speed,

speed = distance /time

Given that the boat is cruising at a constant velocity of 48.3 m/s towards the bridge, substitute the speed and the time to get the distance.

48.3 = distance / 2.143

distance = 48.3 * 2.143

distance = 103.5 m

Therefore,  the boat should be 103.5m away from the bridge at the moment the stunt person jumps?

3 0
3 years ago
Other questions:
  • Sound can travel through a medium, but it does not require a medium.<br> a. True.<br> b. False
    12·1 answer
  • As a system expands, it absorbs 52.5 J of energy in the form of heat from the surroundings. The piston is working against a pres
    5·1 answer
  • How do we convert grams to kilograms
    9·1 answer
  • A marble rolls off a table with a speed of 2.30 m/s. If the table is 1.12 m high, how far from the
    10·1 answer
  • What color is the moon
    7·2 answers
  • A person uses their hand to lift a 0.05-kg guniea pig from the ground at a constand speed.What is the force applied by the perso
    9·1 answer
  • An insulating sphere is 8.00 cm in diameter and carries a 6.50 µC charge uniformly distributed throughout its interior volume.
    14·1 answer
  • Question 2 of 25
    14·1 answer
  • Research and write a short description (3-4 paragraphs) of one of the following parts of the electromagnetic spectrum. Your desc
    9·2 answers
  • A sound wave from a police siren has an intensity of 100.0 W/m² at a certain point; a second sound wave from a nearby ambulance
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!