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
IceJOKER [234]
4 years ago
6

A rocket in deep space has an empty mass of 220 kg and exhausts the hot gases of burned fuel at 2500 m/s. What mass of fuel is n

eeded to reach a top speed of 4000 m/s
Physics
1 answer:
Scilla [17]4 years ago
8 0

Answer:

Explanation:

Let fuel is released at the rate of dm / dt where m is mass of the fuel

thrust created on rocket

= d ( mv ) / dt

= v dm / dt

this is equal to force created on the rocket

= 220 dv / dt

so applying newton's law

v dm / dt = 220 dv / dt

v dm = 220 dv

dv / v = dm / 220

integrating on both sides

∫ dv / v    = ∫ dm / 220

lnv =  ( m₂ - m₁ ) / 220

ln4000 - ln 2500 = ( m₂ - m₁ ) / 220

( m₂ - m₁ ) = 220 x ( ln4000 - ln 2500 )

( m₂ - m₁ ) = 220 x ( 8.29  - 7.82 )

= 103.4 kg .

You might be interested in
Hey guys how to prevent from shock
Pie
U need an insulator to prevent the shock passing through , that's why there is a plastic sheet covering the copper wires so that it can prevent the electricity passing through as plastic is an insulator and does not conduct electricity
8 0
4 years ago
About how long passess between high tides
Virty [35]

about 12 hours I think, since there are two high tides per day

6 0
4 years ago
A 1.8-kg object is attached to a spring and placed on frictionless, horizontal surface. A force of 40 N stretches a spring 20 cm
Sergio [31]

Answer:

a) k = 200 N/m

b) E = 4 J

c) Δx = 6.3 cm

Explanation:

a)

  • In order to find force constant of the spring, k, we can use the the Hooke's Law, which reads as follows:

       F = - k * \Delta x (1)

  • where F = 40 N and Δx =- 0.2 m (since the force opposes to the displacement from the equilibrium position, we say that it's a restoring force).
  • Solving for k:

       k =- \frac{F}{\Delta x} =-\frac{40 N}{-0.2m} = 200 N/m (2)

b)

  • Assuming no friction present, total mechanical energy mus keep constant.
  • When the spring is stretched, all the energy is elastic potential, and can be expressed as follows:

        U = \frac{1}{2}* k* (\Delta x)^{2} (3)

  • Replacing k and Δx by their values, we get:

       U = \frac{1}{2}* k* (\Delta x)^{2} = \frac{1}{2}* 200 N/m* (0.2m)^{2} = 4 J (4)

c)

  • When the object is oscillating, at any time, its energy will be part elastic potential, and part kinetic energy.
  • We know that due to the conservation of energy, this sum will be equal to the total energy that we found in b).
  • So, we can write the following expression:

        \frac{1}{2}* k* \Delta x_{1} ^{2} + \frac{1}{2} * m* v^{2}  = \frac{1}{2}*k*\Delta x^{2}   (5)

  • Replacing the right side of (5) with (4), k, m, and v by the givens, and simplifying, we can solve for Δx₁, as follows:

        \frac{1}{2}* 200N/m* \Delta x_{1} ^{2} + \frac{1}{2} * 1.8kg* (-2.0m/s)^{2}  = 4J   (6)

⇒      \frac{1}{2}* 200N/m* \Delta x_{1} ^{2}   = 4J  - 3.6 J = 0.4 J (7)

⇒     \Delta x_{1}   = \sqrt{\frac{0.8J}{200N/m} } = 6.3 cm (8)

6 0
3 years ago
Sound travels faster in air if the air temperature is :_____
DedPeter [7]

Answer: A) warm

Explanation:

The higher the temperature the faster it travels.

4 0
2 years ago
Una banda de rock toca en un nivel<br>de sonido de 80 dB ¿Cuál es la<br>intensidad de ese sonido?​
BabaBlast [244]
Nsnshsjsnsn nsnsnsnssjsins
4 0
3 years ago
Other questions:
  • The overall length of a piccolo is 32.0 cm. The resonating air column vibrates as in a pipe that is open at both ends. (a) Find
    5·1 answer
  • What is the effect of pressure on the volume of a gas?
    6·2 answers
  • Explain the value or importance of using the international system of units when describing motion
    6·1 answer
  • A billiard ball is moving in the x-direction at 30.0 cm/s and strikes another billiard ball moving in the y-direction at 40.0 cm
    10·1 answer
  • A boat on a river travels downstream between 2 points 20 miles apart in 1 hour. It makes its return trip against the current and
    15·1 answer
  • A force of 203 N is used to move a television 2.3 m. How much work is done?
    12·1 answer
  • What is the amount of heat, in Sl units, necessary to melt 1 lb of ice?
    5·1 answer
  • A vertical piston-cylinder device contains water and is being heated on top of a range. During the process, 63 Btu of heat is tr
    7·1 answer
  • Frosty the Snowman accelerates from 16 m/s to 26 m/s in 2 s. What is his acceleration?
    9·1 answer
  • Create your own food chain​
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!