Just did it
was quite easy, only think i lost 5 marks
the spring question drove me nuts though..could get 0.077
wat did u guys get for phase difference?
also the wave thing...speed is..?
(im tryin not to expose too much lol)
The phase difference is 1.5
. And for the speed, the explanation goes like this :
The incident wave from the oscillator would travel along the string to the other end, P and would be reflected at the same frequency, amplitude and wavelength. The two waves would then experience superposition to form the stationary wave. The speed above is actually the speed of either the incident wave or the reflected wave.
And for your spring question. To get the energy it's actually done the following way :
k = 1.8 N cm
-1 = 180 N m
-1First : The extension of the spring with the load is 2.1cm, so energy for the extension is 1/2 kx
2 = 1/2 (180)(0.021)
2 = E
P1Second : The extension of the spring after added with the force, F is 1.5cm + 2.1cm = 3.6cm, so energy for the extension is 1/2 (180)(0.015+0.021)
2 = E
P2Use E
P2 - E
P1 to get the change in elastic potential energy
By the way, most of the values were 2 significant figures D:
Wtf no :|
I wouldve done the same ven if we had more time. I didnt know how to do the velocity or spring questions
The velocity question was actually to just use your ruler to draw the lines D: And you can actually double check by using the following formula :
Let v
R be the resultant velocity, v
x be the horizontal velocity and v
y be the vertical velocity.
v
R = Square root of (v
x2 + v
y2)
Then the horizontal angle can be found by tan
= v
y/v
xThe vertical angle then can be obtained by 90 -
