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
maksim [4K]
2 years ago
13

A student holds a bike wheel and starts it spinning with an initial angular speed of 9.0 rotations per second. The wheel is subj

ect to some friction, so it gradually slows down. In the 10.0 s period following the inital spin, the bike wheel undergoes 65.0 complete rotations. Assuming the frictional torque remains constant, how much more time Δ t s will it take the bike wheel to come to a complete stop?
Physics
1 answer:
KATRIN_1 [288]2 years ago
6 0

Answer:

\Delta t = 8 s

Explanation:

As we know that the angular acceleration of the wheel due to friction is constant

so we can use kinematics

\theta = \omega_i t + \frac{1}{2}\alpha t^2

so we have

(65 \times 2\pi) = (2\pi \times 9)(10) + \frac{1}{2}(\alpha)(10^2)

130\pi = 180\pi + 50 \alpha

\alpha = -\pi rad/s^2

now time required to completely stop the wheel is given as

\omega_f = \omega_i + \alpha t

0 = (2\pi \times 9) + (-\pi) t

t = 18 s

now time required to stop the wheel is given as

\Delta t = 18 - 10

\Delta t = 8 s

You might be interested in
A magnetic field is directed perpendicular to the plane of a 0.15-m × 0.30-m rectangular coil consisting of 240 loops of wire. T
ValentinkaMS [17]

Answer:

7.344 s

Explanation:

A = 0.15 x 0.3 m^2 = 0.045 m^2

N = 240

e = - 2.5 v

B1 = 0.1 T

B2 = 1.8 T

ΔB = B2 - B1 = 1.8 - 0.1 = 1.7 T

Δt = ?

e = - dФ/dt

e = - N x A x ΔB/Δt

- 2.5 = - 240 x 0.045 x 1.7 / Δt

2.5 = 18.36 / Δt

Δt = 7.344 s

6 0
3 years ago
Which of the following statements describe the steps you need to take to delete a file?
Doss [256]
In order to delete a file, it is required to first select the file which you want to delete and then select 'delete' from the file menu. It will then ask you to confirm the deletion which will be required in order to complete the file deletion process.

It isn't required to click on the X at the top right of the screen or to open the file you want to delete as these steps aren't relevant to the deletion process.

Hence, the statements which describe the steps you need to take in order to delete a file are as follows:

- Confirm the deletion.
- Select Delete from the File menu.
- Select the file you want to delete.
6 0
2 years ago
Read 2 more answers
A shovel is the third class lever​
Nookie1986 [14]

Answer:

Yes

Explanation:

In a third-class lever, the effort force lies between the resistance force and the fulcrum. Some kinds of garden tools are examples of third-class levers. When you use a shovel, for example, you hold one end steady to act as the fulcrum, and you use your other hand to pull up on a load of dirt.

8 0
3 years ago
The weight of the atmosphere above 1 m- of
mars1129 [50]

Answer:

1.09 kg.m

Explanation:

no need

4 0
2 years ago
A sports car accelerates from rest for 5 seconds reaching a velocity of 23.0 m/s.
denis-greek [22]

Answer:

<h2>4.6 m/s²</h2>

Explanation:

The acceleration of an object given it's velocity and time taken can be found by using the formula

<h3>a =  \frac{v - u}{t}  \\</h3>

where

v is the final velocity

u is the initial velocity

t is the time taken

a is the acceleration

Since the body is from rest u = 0

From the question we have

a =  \frac{23 - 0}{5}  =  \frac{23}{5}  \\

We have the final answer as

<h3>4.6 m/s²</h3>

Hope this helps you

4 0
2 years ago
Other questions:
  • According to this graph, which statement describes how the amount of iron changes over time in the reaction
    13·1 answer
  • What is the gravitational potential energy of a rock with the mass of 67 kg if it is sitting on top of a hill .35 kilometers hig
    15·1 answer
  • Suppose you want to test the hypothesis that plants grow taller when they receive more sunlight. Identify and independent variab
    14·1 answer
  • In a lever, the effort arm is two times as long as the load arm. The resultant force will be
    12·1 answer
  • The line spectrum of lithium has a red line at 670.8 nm. Calculate the energy of a photon with this wavelength.
    7·1 answer
  • Consider the incomplete equation below mc020-1.jpg If this equation was completed, which statement would it best support? Nuclea
    11·2 answers
  • A scientist directs monochromatic light toward a single slit in an opaque barrier. The light has a wavelength of 580 nm and the
    6·1 answer
  • A 1090 kg car moving +11.0 m/s
    8·1 answer
  • An object is placed at a distance 30cm from a thin lenses of power 4 diaptor. Discuss the nature of image
    11·1 answer
  • Ahmed fills a basket with shopping weighing 10 kg. How much work is being done on the shopping basket when he lifts it verticall
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!