• We need your support!

    We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
    Click here to Donate Now (View Announcement)

Physics: Post your doubts here!

Messages
1,394
Reaction score
12,123
Points
523
The question states that the water does not rebound off the wall, that means the velocity of the water becomes zero, when it strikes the wall.
The momentum of the water at the mouth of pipe is : mv
The speed is zero at wall, so change in momentum is : mv
Force = rate of change of momentum
Force = mv/t

we are going to consider the force exerted on wall per second, so t=1s

F = mv --(i)

now we need to remove mass 'm' from the above equation.

density = mass/volume
p = m/V => m = p*V

volume of water = A * v

m = p * A * v <--- substitute into (i)

F = p * A * v * v
F = pAv^2

Hence the answer is D.
 
Messages
30
Reaction score
12
Points
18
plz tell me how to solve these type of problems e.g.

a copper wire is to be replaced by an aluminium allow wire of the same length and resistance. copper has half the resistivity of the allow. what is the ratio
diamerter of alloy wire/diameter of copper wire?
i mean every time there is a question like this i can't understand how to solve them

and like this:

fringes of separation x are observed on a screen 1.00m from a double slit that is illuminated by a yellow light of wavelength 600 nm.
at which distance from the slits would fringes of the same separation x be observed when using blue light of wavelength 400nm?
 
Messages
57
Reaction score
36
Points
28
plz tell me how to solve these type of problems e.g.

a copper wire is to be replaced by an aluminium allow wire of the same length and resistance. copper has half the resistivity of the allow. what is the ratio
diamerter of alloy wire/diameter of copper wire?
i mean every time there is a question like this i can't understand how to solve them

and like this:

fringes of separation x are observed on a screen 1.00m from a double slit that is illuminated by a yellow light of wavelength 600 nm.
at which distance from the slits would fringes of the same separation x be observed when using blue light of wavelength 400nm?
for the first apply R=pl/A seperately for both
then get ratio

For the second use lambda= ax/D
you change lambda see how it affects by applying seperately again
 
Messages
179
Reaction score
161
Points
53

Nice username. Sum of vertical upwards momentum = sum of vertical downwards momentum, and sum of horizontal rightwards momentum = sum of horizontal leftwards momemtum.

Using the vertical one, total downwards momentum at end is (0.1)(8.0) = 0.8 N s

So total upwards momentum should be equal to 0.8. Both are 0.05v sin 60, so:

2 x 0.050(v) x sin 60 = 0.8
0.050 (v) = 0.8/(2 x sin 60)
v = 9.23
 
Messages
57
Reaction score
36
Points
28
Nice username. Sum of vertical upwards momentum = sum of vertical downwards momentum, and sum of horizontal rightwards momentum = sum of horizontal leftwards momemtum.

Using the vertical one, total downwards momentum at end is (0.1)(8.0) = 0.8 N s

So total upwards momentum should be equal to 0.8. Both are 0.05v sin 60, so:

2 x 0.050(v) x sin 60 = 0.8
0.050 (v) = 0.8/(2 x sin 60)
v = 9.23
I just typed it in the cal till i got 800 o_o (Life hack btw when you get stuck in q's like this you gotta save time and the name, suits the moment right?) :p :p
 
Messages
59
Reaction score
18
Points
8
plz tell me how to solve these type of problems e.g.

a copper wire is to be replaced by an aluminium allow wire of the same length and resistance. copper has half the resistivity of the allow. what is the ratio
diamerter of alloy wire/diameter of copper wire?
i mean every time there is a question like this i can't understand how to solve them

and like this:

fringes of separation x are observed on a screen 1.00m from a double slit that is illuminated by a yellow light of wavelength 600 nm.
at which distance from the slits would fringes of the same separation x be observed when using blue light of wavelength 400nm?
 

Attachments

  • Screenshot_20170607-235434.png
    Screenshot_20170607-235434.png
    1.7 MB · Views: 11
Messages
59
Reaction score
18
Points
8
plz tell me how to solve these type of problems e.g.

a copper wire is to be replaced by an aluminium allow wire of the same length and resistance. copper has half the resistivity of the allow. what is the ratio
diamerter of alloy wire/diameter of copper wire?
i mean every time there is a question like this i can't understand how to solve them

and like this:

fringes of separation x are observed on a screen 1.00m from a double slit that is illuminated by a yellow light of wavelength 600 nm.
at which distance from the slits would fringes of the same separation x be observed when using blue light of wavelength 400nm?
 

Attachments

  • Screenshot_20170608-001247.png
    Screenshot_20170608-001247.png
    1.8 MB · Views: 7
Messages
59
Reaction score
18
Points
8
Hey guys have you all gone to sleep. :sleep:
we need to increase the number of nuclei present because .....a particles are deflected by large angles when they hit the nucleus of the atom ..so the only valid option is C ..by using double thickness foil number of nuclei increases nd a larger propotion of a particles are deflected
 
Messages
438
Reaction score
3,645
Points
253
we need to increase the number of nuclei present because .....a particles are deflected by large angles when they hit the nucleus of the atom ..so the only valid option is C ..by using double thickness foil number of nuclei increases nd a larger propotion of a particles are deflected
thanks
 
Top