Asked by Alex

3)
a) Calculate the unstretched length of a spring, which has a Hooke's constant of 40N/m and is 56cm long when supporting a stationary 800g object.

I did
mag = kx
(0.800)(9.81) = 40x
x = 0.20m

l-x = u
56-20 = u
u = 36cm

Is that right?

b) The period with which the object would oscillate vertically.
I did
T = 2pi sqrt(0.800/40)
and got 0.9s...is that right?

c) The amplitude that would be required so that the object's maximum speed while oscillating would be 160cm/s. Then suggest why an oscillation is not possible with this spring.

I don't understand how to calculate that.

6) If a flea has a mass of 2.0x10^2 micrograms jumps vertically to a height of 65mm and 75% of the energy comes from elastic potential energy stored in the protein, determine the initial quantity of elastic potential energy.


Answers

Answered by drwls
3(a) and (b) look OK. For 3(c), use
(1/2)MVmax^2 = (1/2) kX^2 and solve for the maximum amplitude X. If X exceeds the unstretched spring length, such an oscillation is not possible, since you can't compress the spring to a negative length.

For (6), use
(1/2)M g H = (0.75)E where E is the potential energy stored in protein and H is the height that the flea can jump.
Answered by Alex
I got 23cm using that formula for 3a. Should I add that to 36? I don't get it.
There are no AI answers yet. The ability to request AI answers is coming soon!

Related Questions