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
PilotLPTM [1.2K]
3 years ago
6

A small block on a frictionless, horizontal surface has a mass of 0.0250 kg. It is attached to a massless cord passing through a

hole in the surface. The block is originally revolving at a distance of 0.300 m from the hole with an angular speed of 1.75 rad/s. The cord is pulled from below, shortening the radius of the circle in which the block revolves to 0.150 m. Model the block as a point particle. (a) Is the angular momentum of the block conserved? Why or why not? (b) What is the new angular speed? (c) Find the change in kinetic energy of the block.
Physics
1 answer:
frosja888 [35]3 years ago
6 0

Answer:

a) Yes

b) 7 rad/s

c) 0.01034 J

Explanation:

a)

Yes the angular momentum of the block is conserved since the net torque on the block is zero.

b)

m = mass of the block = 0.0250 kg

w₀ = initial angular speed before puling the cord = 1.75 rad/s

r₀ = initial radius before puling the cord = 0.3 m

w = final angular speed after puling the cord = ?

r = final  radius after puling the cord = 0.15 m

Using conservation of angular momentum

m r₀² w₀ = m r² w

r₀² w₀ = r² w

(0.3)² (1.75) = (0.15)² w

w = 7 rad/s

c)

Change in kinetic energy is given as

ΔKE = (0.5) (m r² w² - m r₀² w₀²)

ΔKE = (0.5) ((0.025) (0.15)² (7)² - (0.025) (0.3)² (1.75)²)

ΔKE = 0.01034 J

You might be interested in
A rectangular block of copper metal weighs 1896 g. The dimensions of the block are 8.4 cm by 5.5 cm by 4.6 cm. From this data, w
sp2606 [1]

Answer:

8.9 g/cm^3

Explanation:

density = mass/volume

volume = length * width * height

volume = (8.4 cm)(5.5 cm)(4.6 cm)

volume = 212.52 cm^3

mass = 1896 g

density = (1896 g)/(212.52 cm^3)

density = 8.9 g/cm^3

3 0
3 years ago
A prismatic bar AB of length L and solid circular cross section (diameter d) is loaded by a distributed torque of constant inten
Lyrx [107]

Answer:

a) the maximum shear stress τ_{max} the bar is 16T_{max} /πd³

b) the angle of twist between the ends of the bar is 16tL² / πGd⁴  

Explanation:

Given the data in the question, as illustrated in the image below;

d is the diameter of the prismatic bar of length AB

t is the intensity of distributed torque

(a) Determine the maximum shear stress tmax in the bar

Maximum Applied torque  T_max = tL

we know that;

shear stress τ = 16T/πd³

where d is the diameter

so

τ_{max} = 16T_{max} /πd³

Therefore, the maximum shear stress τ_{max} the bar is 16T_{max} /πd³

(b) Determine the angle of twist between the ends of the bar.

let theta (\theta) be the angle of twist

polar moment of inertia I_p} = πd⁴/32

now from the second image;

lets length dx which is at distance of "x" from "B"

Torque distance x

T(x) = tx

Elemental angle twist = d\theta = T(x)dx / GI_{p}

so

d\theta = tx.dx / G(πd⁴/32)

d\theta = 32tx.dx / πGd⁴

so total angle of twist \theta will be;

\theta =  \int\limits^L_0  \, d\theta

\theta =  \int\limits^L_0  \, 32tx.dx / πGd⁴

\theta = 32t / πGd⁴  \int\limits^L_0  \, xdx

\theta = 32t / πGd⁴ [ L²/2]

\theta = 16tL² / πGd⁴  

Therefore,  the angle of twist between the ends of the bar is 16tL² / πGd⁴  

7 0
3 years ago
In deep space, there is very little friction. Once they launch a probe into deep space, where there are no external forces actin
Charra [1.4K]

Answer:

move at constant velocity.

Explanation:

Newton's first law (also known as law of inertia) states that:

"when the net force acting on an object is zero, the object will keep its state of rest or if it is moving, it will continue moving at constant velocity".

In the case of the probe, friction in deep space is negligible, therefore when the engine is shut down, there are no more forces acting on the probe: the net force therefore will be zero, so the probe will move at constant velocity.

5 0
2 years ago
Read 2 more answers
When the area over which pressure is applied is increased,
Tema [17]

Answer:

A. the pressure decrease

Explanation:

pressure decreases when the surface area over which a force is applied increases. pressure increases when the surface area over which force is applied decreases.

3 0
3 years ago
What number and type of hybrid orbital(s) form(s) when one p and one s atomic orbital mix?
Harrizon [31]

Two equivalent hybridized orbitals will form from the mixing of one s-orbital and one p-orbital, that is (sp) orbital.

<h3>What are orbitals?</h3>

Orbital is the place around nucleus where mostly the electrons are present. There are four types of orbitals are present, s, p, d, and f.

The orbitals that are formed by the mixing of these orbitals are called hybrid orbitals.

Thus, two equivalent hybridized orbitals will form from the mixing of one s-orbital and one p-orbital, that is (sp) orbital.

Learn more about orbitals

brainly.com/question/18914648

#SPJ4

3 0
2 years ago
Other questions:
  • What planet has the least amount of inertia
    7·1 answer
  • Consider the following equations. 3 A + 6 B → 3 D, ΔH = -446 kJ/mol E + 2 F → A, ΔH = -107.9 kJ/mol C → E + 3 D, ΔH = +61.9 kJ/m
    8·1 answer
  • What type of tide occurs on a full moon or a new moon?
    5·2 answers
  • A box is dropped onto a conveyor belt moving at 3.2 m/s. If the coefficient of friction between the box and the belt is 0.28, ho
    7·1 answer
  • An increase in temperature the kinetic energy and average speed of the gas particles. As a result, the pressure on the walls of
    8·1 answer
  • One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a s
    7·1 answer
  • Does anyone know 08fortnitebeast?
    12·1 answer
  • The physics of wind instruments is based on the concept of standing waves. When the player blows into the mouthpiece, the column
    12·1 answer
  • What is salinity ? ..​
    11·2 answers
  • A 3.1 kg ball is dropped from the top of a 38 m tall building. What is the speed of the ball when it is halfway from the buildin
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!