Help solve all this question please

  • Thread starter Thread starter tauwee
  • Start date Start date
AI Thread Summary
The discussion revolves around a collision problem involving two spheres, P and Q, with different masses and speeds. The key points include finding the post-collision velocities of both spheres in terms of the initial speed and the coefficient of restitution, e. It is established that if sphere P changes direction after the collision, then e must be greater than 1/3. Additionally, the problem requires deriving an expression for the velocity of sphere Q after the collision and demonstrating that the coefficient of restitution between Q and a wall is greater than 1/9 when e is given as 5/9. The coefficient of restitution is defined as the ratio of relative speeds after and before the collision, indicating how elastic the collision is.
tauwee
Messages
3
Reaction score
0
help solve all this question please...:(

A uniform smooth sphere P,of mass 3m, is moving in a straight line with speed u on a smooth horizontal table.Another uniform smooth sphere Q, of mass and m and having the same radius as P, moving with speed 2u in the same straight line as P but in the opposite direction to P. The sphere P collides with the sphere Q directly. The velocities of P and Q after the collision are v and w respectively, measured in the direction of motion of P before the collision. The coefficient of restitution between P and Q is e.

a) Find an expression for v in terms of u and e.
b) Show that, if the direction of motion and P is changed by the collision, then e>1/3.
c) Find an expression for w in terms of u and e.

Following the collision with P, the sphere Q then collides with and rebounds from a vertical wall which is perpendicular to the direction of motion of Q. The coefficient of restitution between Q and the wall is e'

Given that e=5/9, and that P and Q collide again in the subsequent motion,
e) Show that e'>1/9.
 
Physics news on Phys.org
Do you know any equations that may help?
 
this is the prove question...i don't know wht equation can solve :(
 
Can you define " The coefficient of restitution"?
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
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...
Back
Top