How can you determine initial velocity without the given information?

AI Thread Summary
To determine the initial velocity of a ball that must bounce through an opening between 3.1-4.9 feet high, one can use the angle and height provided in the problem. The correct initial velocity is approximately 15-20 ft/s. The discussion highlights the importance of showing working steps to identify where issues may arise in calculations. A user successfully solved the problem after some manipulation of the given data. This emphasizes the value of persistence and collaboration in solving physics problems.
Jason03
Messages
161
Reaction score
0
[SOLVED] Initial velocity not given

Hello,
I was looking for a strategy for finding the initial velocity for a problem that gives the angle and height. The problem is: A ball is dropped and rebounds with an intial velocity of what magnitude considering the ball must bounce through an opening that is between 3.1-4.9 feet high.

I tried some manipulation but couldn't get the correct answer...which is around 15-20 ft/s

Thanks
 
Physics news on Phys.org
Last edited by a moderator:
Thanks...I actually figured it out...
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top