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
Nesterboy [21]
3 years ago
6

You push very hard on a heavy desk, trying to move it. You do work on the desk:

Physics
1 answer:
frozen [14]3 years ago
3 0

Answer:

(C) Only if it starts moving

Explanation:

We know that work done is given by

W=F.d=Fdcos\Theta

So there are two case in which work done is zero

First case is that when force and displacement are perpendicular to each other

And other case is that when there is no displacement

So for work to be done there must have displacement, if there is no displacement then there is no work done

So option (c) will be the correct option

You might be interested in
A rocket engine has a chamber pressure 4 MPa and a chamber temperature of 2000 K. Assuming isentropic expansion through the nozz
gladu [14]

This question is incomplete, the complete question is;

A rocket engine has a chamber pressure 4 MPa and a chamber temperature of 2000 K. Assuming isentropic expansion through the nozzle, and an exit Mach number of 3.2, what are the stagnation pressure and temperature in the exit plane of the nozzle?  Assume the specific heat ratio is 1.2.

Answer:

- stagnation pressure is 274.993 Mpa

- the stagnation temperature Tt is 4048 K

Explanation:

Given the data in the question;

To determine the stagnation pressure and temperature in the exit plane of the nozzle;

we us the expression;

Pt/P = (1 + (γ-1 / 2) M²)^(γ/γ -1) = ( Tt/T )^(γ/γ -1)

where Pt is stagnant pressure = ?

P is static pressure = 4 MPa = 4 × 10⁶ Pa  

Tt is stagnation temperature = ?

T is the static temperature  = 2000 K

γ is ratio of specific heats = 1.2

M is Mach number M = 3.2

we substitute

Pt/P = (1 + (γ-1 / 2) M²)^(γ/γ -1)

Pt = P(1 + (γ-1 / 2) M²)^(γ/γ -1)

Pt = 4 × 10⁶(1 + (1.2-1 / 2) 3.2²)^(1.2/1.2 -1)

Pt = 4 × 10⁶ × 68.7484

Pt = 274.993 × 10⁶ Pa

Pt = 274.993 Mpa

Therefore stagnation pressure is 274.993 Mpa

Now, to get our stagnation Temperature

Pt/P = ( Tt/T )^(γ/γ -1)

we substitute

274.993 × 10⁶ Pa / 4 × 10⁶ Pa =  ( Tt / 2000 )^(1.2/1.2 -1)

68.7484 =  Tt⁶ / 6.4 × 10¹⁹

Tt⁶ = 68.7484 × 6.4 × 10¹⁹

Tt⁶ = 4.3998976 × 10²¹

Tt = ⁶√(4.3998976 × 10²¹)

Tt = 4047.999 ≈ 4048 K

Therefore, the stagnation temperature Tt is 4048 K

6 0
3 years ago
A kid applies a force of 70 N to a ball over 1.1 meters. How much work did he do on the ball?
LekaFEV [45]

Answer:

77J

Explanation:

Not really an explanation to this, I just had this lesson last year and remembered it.

Hope I helped! ☺

8 0
3 years ago
A large box slides across a frictionless surface with a velocity of 12 m/s and a mass of 4
denpristay [2]
Answer= 8m/s

Because total Momentum before= total momentum after

Momentum before (p=mu)
p=(4)(12)= 48
p=2(0)=0
So total momentum before=48

Momentum after (p=mu)
Masses combined —2+4=6kg
p=6u


Mb=Ma
48=6u
u=8m/s
3 0
2 years ago
DESCRIBE THE REQUIREMENTS OF AN INTERNET CONNECTION?<br>please tell me the answer​
AlekseyPX

Answer: The basic requirements for connecting to the Internet are a computer device, a working Internet line, and the right modem for that Internet line. In addition, software programs such as Internet browsers, email clients, Usenet clients, and other special applications are needed in order to access the Internet.

Explanation: brainleist pls :)

4 0
3 years ago
A factory line moves parts for an automobile at a constant speed of 0.22 m/s. How long does it take the parts to move 8.5 m alon
OleMash [197]

Answer: C. 39 s

Explanation:

We know the constant speed is 0.22 m/s. We have to get to 8.5 m. We divide <u>8.5 m by 0.22</u> = 38.6. After we estimate, 6 is greater than 5, so 39 s.

5 0
3 years ago
Other questions:
  • What is the difference between reflection and refraction
    5·1 answer
  • Once again we have a skier on an inclined plane. The skier has mass M and starts from rest. Her speed at the bottom of the slope
    8·1 answer
  • A 42 N net force is applied to a box which slides horizontally across a floor for 9.0
    9·1 answer
  • A. If you have a Periodic Table that is NOT color coded, describe WHERE to look on the Periodic Table to find elements which hav
    11·2 answers
  • Match the description to the property.
    8·1 answer
  • Why is the unit of temperature is called derived unit<br><br>​
    14·1 answer
  • The electrostatic attractions in crystalline salts, such as sodium chloride, are formed by __________ between positive and negat
    8·2 answers
  • A current of 15 Amps flows through a circuit with a resistance of 0.10 Ohms. What is the voltage?
    15·1 answer
  • what will be the focal lenght of a combined lens made by contact of two lenses of power +3D and -2D.​
    11·1 answer
  • A builder drops a brick from a height of 15 m above the ground. The gravitational field strength g is 10 N/ kg. What is the spee
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!