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
never [62]
3 years ago
8

A hoop of mass 2 kg, radius 0.5 m is rotating about its center with an angular speed of 3 rad's. A force of 10N is applied tange

ntially at the rim (a) Determine the rotational kinetic energy oh the hoop (b) What is instantaneous change rate of the kinetic energy?
Physics
1 answer:
Degger [83]3 years ago
3 0

Answer:

The rotational kinetic energy of the hoop and the instantaneous change rate of the kinetic energy are 2.25 J and 15 J.

Explanation:

Given that,

Mass = 2 kg

Radius = 0.5 m

Angular speed = 3 rad/s

Force = 10 N

(I). We need to calculate the rotational kinetic energy

Using formula of kinetic energy

K.E =\dfrac{1}{2}\timesI\omega^2

K.E=\dfrac{1}{2}\times mr^2\times\omega^2

K.E=\dfrac{1}{2}\times2\times(0.5)^2\times(3)^2

K.E=2.25\ J

(II). We need to calculate the instantaneous change rate of the kinetic energy

Using formula of kinetic energy

K.E=\dfrac{1}{2}mv^2

On differentiating

\dfrac{K.E}{dt}=\dfrac{1}{2}m\times2v\times\dfrac{dv}{dt}

\dfrac{K.T}{dt}=mva....(I)

Using newton's second law

F = ma

a= \dfrac{F}{m}

a=\dfrac{10}{2}

a=5 m/s^2

Put the value of a in equation (I)

\dfrac{K.E}{dt}=mva

\dfrac{K.E}{dt}=mr\omega a

\dfrac{K.E}{dt}=2\times0.5\times3\times5

\dfrac{K.E}{dt}=15\ J/s

Hence, The rotational kinetic energy of the hoop and the instantaneous change rate of the kinetic energy are 2.25 J and 15 J.

You might be interested in
Thalia is drafting a plan to move a large, perfect sphere concrete sculpture that is in front of her office building. Describe t
Marina86 [1]
For the answer to this question, 
Thalia must consider the weight of the object and the mass of the sculpture. Weight and mass are different things. She should also consider the time on how long it will take to move it and where she'll move it.
4 0
3 years ago
Read 2 more answers
Which is faster, light or sound? Explain.
Lemur [1.5K]
Light travels faster than sound ,because sound can only travel waves.
5 0
3 years ago
Read 2 more answers
A car with a total mass of 1800 kg (including passengers) is driving down a washboard road with bumps spaced 4.9 m apart. The ri
Drupady [299]

Answer:

k = 9.6 x 10^5 N/m or 9.6 kN/m

Explanation:

First, we need to use the expression to calculate the spring constant which is:

w² = k/m

Solving for k:

k = w²*m

To get the angular velocity:

w = 2πf

The problem is giving the linear velocity of the car which is 5.7 m/s. With this we can calculate the frequency of the car:

f = V/x

f = 5.7 / 4.9 = 1.16 Hz

Now the angular velocity:

w = 2π*1.16

w = 7.29 rad/s

Finally, solving for k:

k = (7.29)² * 1800

k = 95,659.38 N/m

In two significant figures it'll ve 9.6 kN/m

5 0
3 years ago
Read 2 more answers
You want the current amplitude through a 0.450-mH inductor (part of the circuitry for a radio receiver) to be 1.90 mA when a sin
faust18 [17]

Answer:

Frequency required will be 2421.127 kHz

Explanation:

We have given inductance L=0.450H=0.45\times 10^{-3}H

Current in the inductor i=1.90mA=1.90\times 10^{-3}A

Voltage v = 13 volt

Inductive reactance of the circuit X_l=\frac{v}{i}

X_l=\frac{13}{1.9\times 10^{-3}}=6842.10ohm

We know that

X_l=\omega L=2\pi fL

2\times 3.14\times  f\times 0.45\times 10^{-3}=6842.10

f = 2421.127 kHz

6 0
3 years ago
What is the force of gravity between two 40.0kg masses that are separated by 3.00m?
Slav-nsk [51]

Answer:

f = g \times \frac{m1 \times m2}{ {d}^{2} }

f = 6.67 \times  {10}^{ - 11}  \times \frac{40 \times 40}{9}

<h2>F=1.2x 10^-8</h2>
3 0
3 years ago
Other questions:
  • The potential in a region of space due to a charge distribution is given by the expression V = ax2z + bxy − cz2 where a = −3.00
    14·1 answer
  • The number of outer shell electrons determines the chemical properties of an element?
    14·1 answer
  • In tin at room temperature, the mobility of mobile electrons is about 1.5 ✕ 10⁻³ (m/s)/(V/m), and there are about 3.7 ✕ 10²⁸ mob
    12·1 answer
  • 1. The speaker uses needles from two
    15·1 answer
  • Imagine that the ball on the left is given a nonzero initial velocity in the horizontal direction, while the ball on the right c
    6·1 answer
  • Can someone please help, ty!
    10·1 answer
  • 40 Points!!!!!!!
    5·2 answers
  • Suppose a ray of light traveling in a material with an index of refraction na reaches an interface with a material having an ind
    7·1 answer
  • Two different electrical devices have the same power consumption, but one is meant to be operated on 120-V AC and the other on 2
    8·1 answer
  • Write a short story (3 - 5 sentences) that describes a situation with the motion experiences in this graph. Please Help Me.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!