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
Anuta_ua [19.1K]
3 years ago
14

A car traveling at 7.0 m/s accelerates uniformly at 2.5 m/s2 to reach a speed of 12.0 m/s. how long does it take this accelerati

on to occur
Physics
1 answer:
lina2011 [118]3 years ago
4 0
Vf=Vi+at
12=7+2.5t
5=2.5t
t=2s
You might be interested in
Air contained in a rigid, insulated tank fitted with a paddle wheel, initially at 300 K, 2 bar, and a volume of 3 m3, is stirred
madam [21]

Answer:

a)P₂ =4 bar

b)W= - 1482.48 KJ

It means that work done on the system.

c)S₂ - S₁ = 3.42 KJ/K

Explanation:

Given that

T₁ = 300 K   ,V₁ = 3 m³  ,P₁=2 bar

T₂ = 600 K ,V₂=V₁ 3 m³

Given that tank is rigid and insulated.It means that volume of the gas will remain constant.

Lets take the final pressure = P₂

For ideal gas  P V = m R T

\dfrac{P_2}{P_1}=\dfrac{T_2}{T_1}

P_2=\dfrac{T_2}{T_1}\times P_1

P_2=\dfrac{600}{300}\times 2

P₂ =4 bar

Internal energy

ΔU = m Cv ΔT

Cv=0.71 KJ/kg.k for air

m=\dfrac{PV}{RT}

m=\dfrac{200\times 3}{0.287\times 300}\ kg

m= 6.96 kg

ΔU= 6.96 x 0.71 x (600 - 300)

ΔU=1482.48 KJ

From first law

Q= ΔU + W

Q= 0  Insulated

W = - ΔU

W= - 1482.48 KJ

It means that work done on the system.

Change in the entropy

S_2-S_1=mC_v\ \ln\dfrac{T_2}{T_1}

S_2-S_1=6.96\times 0.71\ \ln\dfrac{600}{300}

S₂ - S₁ = 3.42 KJ/K

 

5 0
3 years ago
Difference between work done against gravity and friction​
mario62 [17]
Mark Brainliest please


Friction is a nonconservative force. Therefore work done against friction cannot be stored as potential energy and later converted back to kinetic the way work against gravity can.

Gravity always pulls objects such as a desk, book or person down. Thus, when you jump, gravity causes you to land on the ground. Friction, however, doesn't pull objects down. ... Instead friction occurs when something like a machine or individual pulls a sliding object in the opposite direction of another object.


Friction and gravity exist in every aspect of a person’s life. For example, almost every movement you make, such as walking and running, involves friction. When you throw a ball up, gravity causes the ball to fall down. A person sliding a book across a table creates friction. Nevertheless, differences between gravity and friction also exist. Force affects gravity and friction in different ways.
8 0
3 years ago
Define mechanics and describe its three major divisions
Andrew [12]

<u>Mechanics</u> is the branch of physics which deals with the study of motion of material objects.

<u><em>Divisions</em></u>

There are three major division of mechanics

Statics

Kinematics

Dynamics.

4 0
2 years ago
Joe the house painter stands on a uniform oak board weighing 600 N and held up by vertical ropes at each end. Joe has been dieti
Mamont248 [21]

Answer

given,

weight of the oak board = 600 N

Weight of Joe = 844 N

length of board = 4 m

Joe is standing at 1 m from left side

vertical wire is supporting at the end.

Assuming the system is in equilibrium

T₁ and T₂ be the tension at the ends of the wire

equating all the vertical force

T₁ + T₂ = 600 + 844

 T₁ + T₂ = 1444...........(1)

taking moment about T₂

 T₁ x 4 - 844 x 3 - 600 x 2 = 0

 T₁ x 4 = 3732

 T₁ = 933 N

from equation (1)

 T₂ = 1444 - 933

 T₂ = 511 N

3 0
3 years ago
As speed (velocity) increases, potential energy increases true or false
Lyrx [107]

Answer:

true

Explanation:

3 0
2 years ago
Other questions:
  • Which way does wind blow
    13·2 answers
  • How does distance between two objects affect their gravitational force
    9·1 answer
  • Describe how the mass, luminosity, surface temperature, and radius of main-sequence stars change in value going from the “bottom
    14·1 answer
  • How many protons, neutrons, and electrons does a neutral atom of this element have? (round atomic mass to nearest whole number)
    6·2 answers
  • Nisha was making a list of things that are obtained from plants and Amol was making a list of things that can dissolve in water.
    7·1 answer
  • I’m on a test please help me
    10·1 answer
  • CHEGG In the final stages of production, a pharmaceutical is sterilized by heating it from 25 to 75C as it moves at 0.2 m/s thro
    10·1 answer
  • How long does a player sit out of a game of handball for committing a second or third foul?
    8·1 answer
  • HELPPP PLEASE URGENT
    9·1 answer
  • Which part of a laser printer applies a positive charge to the paper that attracts the toner particles to it
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!