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
True [87]
2 years ago
13

A book weighs 0.5 kilograms on a book shelf that is 2 meters above the ground. What is the potential energy of the book relative

to the ground? (HINT: you may use 10 N/kg as the value for gravity)
Physics
1 answer:
Elena L [17]2 years ago
5 0
Using the GPE=MGH, M=0.5 kg, G=9.8m/s H= 2 m multiply those all together and we will have 9.8 J (joules)
You might be interested in
FIGURE 2 shows a 1.5 kg block is hung by a light string which is wound around a smooth pulley of radius 20 cm. The moment of ine
Sindrei [870]

Answer:

At t = 4.2 s

Angular velocity: 6. 17 rad /s

The number of revolutions: 2.06

Explanation:

First, we consider all the forces acting on the pulley.

There is only one force acting on the pulley, and that is due to the 1.5 kg mass attached to it.

Therefore, the torque on the pulley is

\tau=Fd=mg\cdot R

where m is the mass of the block, g is the acceleration due to gravity, and R is the radius of the pulley.

Now we also know that the torque is related to angular acceleration α by

\tau=I\alpha

therefore, equating this to the above equation gives

mg\cdot R=I\alpha

solving for alpha gives

\alpha=\frac{mgR}{I}

Now putting in m = 1.5 kg, g = 9.8 m/s^2, R = 20 cm = 0.20 m, and I = 2 kg m^2 gives

\alpha=\frac{1.5\cdot9.8\cdot0.20}{2}\boxed{\alpha=1.47s^{-2}}

Now that we have the value of the angular acceleration in hand, we can use the kinematics equations for the rotational motion to find the angular velocity and the number of revolutions at t = 4.2 s.

The first kinematic equation we use is

\theta=\theta_0+\omega_0t+\frac{1}{2}\alpha t^2

since the pulley starts from rest ω0 = 0 and theta = 0; therefore, we have

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

Therefore, ar t = 4.2 s, the above gives

\theta=\frac{1}{2}(1.47)(4.2)^2

\boxed{\theta=12.97}

So how many revolutions is this?

To find out we just divide by 2 pi:

\#\text{rev}=\frac{\theta}{2\pi}=\frac{12.97}{2\pi}\boxed{\#\text{rev}=2.06}

Or about 2 revolutions.

Now to find the angular velocity at t = 4.2 s, we use another rotational kinematics equation:

\omega^2=w^2_0+2\alpha(\Delta\theta)_{}

Since the pulley starts from rest, ω0 = 0. The change in angle Δθ we calculated above is 12.97. The value of alpha we already know to be 1.47; therefore, the above becomes:

\omega^2=0+2(1.47)(12.97)w^2=38.12\boxed{\omega=6.17.}

Hence, the angular velocity at t = 4.2 w is 6. 17 rad / s

To summerise:

at t = 4.2 s

Angular velocity: 6. 17 rad /s

The number of revolutions: 2.06

3 0
1 year ago
Sort the statements about heat transfer into the correct columns.
Hoochie [10]

Answer: Conduction- Touch transfer heat and Earth warms air

Convection- liquid/gas transfers heat and warm air rises

Radiation- Sun heats Earth and Waves transfer heat

Explanation:

5 0
3 years ago
Read 2 more answers
Explain why it takes more energy to remove the second electron from a lithium atom than it does to remove the fourth electron fr
slava [35]
It takes more energy to remove the second electron from a lithium atom than it does to remove the fourth electron from a carbon atom because its inner core e, not valence e. C's 4th removed e is still a valence e. And also <span>because more nuclear charge acting on the second electron, it is more close to the nucleus, thus the the protons attract it more than the 4th electron.</span>
8 0
3 years ago
Read 2 more answers
A runner covers 40 m in 4.55 seconds ,what is their average velocity?
goldenfox [79]

Velocity = displacement/time



I hope i helped you <33

3 0
3 years ago
Do acids or bases turn litmus paper red?
Tom [10]
Base => Blue

aciD => reD
5 0
3 years ago
Other questions:
  • 1) what is a calorie?<br>​
    9·1 answer
  • Find the probability density of a particle moving in an interval of 101o the box. The length of the one-dimensional box is 20x10
    7·1 answer
  • Написать сочинение на тему маленький человечек​
    13·1 answer
  • A ______ is a network that has all connected devices located in the same physical location.
    8·1 answer
  • Kinetic energy is based on position.
    13·1 answer
  • If the equation of an average velocity of a sport car was given by the equation V(t) = 3t^2 -6t +24. Determine its displacement
    11·1 answer
  • While preforming an experiment involving a reaction between two chemicals the scientist observes that the reaction container has
    11·1 answer
  • What was the name of the first man made satellite launched by the Soviet Union in 1957.​
    15·1 answer
  • ………………………….. yeah I know I was just looking looking at the guy that was like yeah yeah I know it’s crazy but ……………………..
    10·2 answers
  • What tool would you use for Volume
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!