Answer:
B) 4.0m
Explanation:
The work done to launch the spacecraft in low earth orbit is
The gravitational force is a conservative force. So, the total energy of the system must be conserved.
According to the work-energy theorem:
work done = - change in potential energy of the system.
W = -ΔPE
Initially, the potential energy of the satellite on the surface is:
PE =
where m is the mass of the satellite
Let the orbit be at a height of h from the surface, so the potential energy in the orbit is :
PE' =
ΔPE = PE'-PE
ΔPE =
Now work done:
W = - ΔPE
Thus,
Learn more about work energy theorem:
Answer:
Work done to shift the spacecraft from Earth surface to low Earth radius is given as
Explanation:
As we know that spacecraft is at surface of Earth initially
So we will have
now when it is at low radius Earth Orbit then we have
now we know that work done to shift the spacecraft from Earth Surface to Low earth orbit is change in total energy
so we have
since we know h << Re
so work done is given as
Answer:
Height covered after crossing window top = 0.75 m
Explanation:
In the question,
The height of the window pane = 1.8 m
Time for which the flowerpot is in view = 0.66 s
So,
The time for which it was in view while going up is = 0.33 s
Time for which it was in view while going down = 0.33 s
So,
Let us say,
The initial velocity of the flowerpot = u m/s
So,
Using the equation of the motion,
So,
Velocity at the top of the window pane is given by,
Now,
Let us say the height to which the flowerpot goes after crossing the window pane is = h
So,
Using the equation of motion,
Therefore, the height covered by the flowerpot after window is = 0.75 m
b. The dark lines are at higher energies than the bright lines.
c. The bright lines are at higher energies than the dark lines.
d. You cannot relate the two types of spectra.
The dark absorption lines of an atom's spectrum correspond to the same energies as the bright emission lines. They both reflect energy changes in electron states.
The dark lines of an atom's absorption spectrum are at the same energies as the bright lines of its emission spectrum, therefore the correct answer is a. The bright lines are at the same energies as the dark lines. Absorption spectra are produced when electrons absorb energy and move to a higher energy level, while emission spectra are observed when electrons lose energy and return to a lower energy level.
The dark lines (absorption) and bright lines (emission) coincide because the energy required to move an electron from a lower to higher energy level matches the energy released when an electron drops from a higher to lower state.
#SPJ12
The speed are they moving at will be 0.5 m/sec.Law of conservation of momentum is applied.
According to the law of conservation of momentum, the momentum of the body before the collision is always equal to the momentum of the body after the collision.
The given data in the problem is;
(m₁) is the mass of 1st gilder= 0.40 kg
(u₁) is the initial velocity = 2 m/s
(m₂) is the mass of 2nd gilder = 1.20 kg
(u₂) is the initial velocity of 2nd gilder = 0 m/s
(v) is the velocity after collision =.?
According to the law of conservation of momentum;
Momentum before collision =Momentum after collision
Hence, the speed are they moving at will be 0.5 m/sec
To learn more about the law of conservation of momentum refer;
#SPJ2
b. induction.
c. static electricity.
d. friction.
Answer : The correct answer is- D) Friction.
There are three modes of charging, which are Conduction, induction, and friction.
The static electricity is produced due to the rubbing of one substance with another. This is called charing by friction.
Hence, the correct answer is friction as there is friction between carpet and the feet of person walking over it.
Walking across a carpet is an example of charge being transferred by friction. The answer is letter D. The carpet, which is at rest, will resist the motion cause by your walking. This resistive motion d the friction the carpet obtained from you and you from the carpet.
The mass of solid formed is 2.654 g
calculation
step 1: write the balanced molecular equation
=2AgNO3(aq) + k2CrO4(aq)→ Ag2CrO4(s) + 2 KNO3(aq)
step 2: calculate the moles of K2CrO4
moles = molarity x volume in liters
molarity = 0.200 M = 0.200 mol/L
volume = 40 .0 ml in liters = 40/1000 = 0.04 liters
moles is = 0.200 mol/l x0.04 L =0.008 moles
Step 3: use the mole ratio to determine the moles of solid formed( Ag2CrO4)
K2CrO4 :Ag2CrO4 is 1:1 therefore the moles of Ag2CrO4 is also
0.008 moles
step 4: calculate the mass of Ag2CrO4
mass = moles x molar mass
from periodic table the molar mass of Ag2Cro4
=(107.87 x2) + 52 +(16 x4) =331.74 g/mol
mass = 0.008 moles x 331.74 = 2.654 g