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Question Number 215256 by ajfour last updated on 01/Jan/25

Commented by ajfour last updated on 01/Jan/25

After this elastic collision on a flat  frictionless surface Find after what  time at what y coordinate does point  A cross the y-axis.

AfterthiselasticcollisiononaflatfrictionlesssurfaceFindafterwhattimeatwhatycoordinatedoespointAcrosstheyaxis.

Commented by ajfour last updated on 02/Jan/25

https://youtu.be/roXqnV-fZ7k?si=JafblceCGUAmx3u- My video lecture discussing a problem of finding spring extension when to each end of it is attached a positive charge q.

Answered by mr W last updated on 02/Jan/25

Commented by mr W last updated on 02/Jan/25

I_1 =I_2 =((mL^2 )/(12))  mv_1 =J  I_1 ω_1 =((JL)/4)  ⇒ω_1 =((3v_1 )/L)  mu_2 =mu cos 30°  ⇒u_2 =(((√3)u)/2)  mv_2 =mu sin 30°−J  ⇒v_2 =(u/2)−v_1   I_2 ω_2 =−J×((L cos 30°)/2)  ⇒ω_2 =−((3(√3)v_1 )/L)  (m/2)(v_1 ^2 +u_2 ^2 +v_2 ^2 )+(1/2)×((mL^2 )/(12))(ω_1 ^2 +ω_2 ^2 )=((mu^2 )/2)  v_1 ^2 +((((√3)u)/2))^2 +((u/2)−v_1 )^2 +(L^2 /(12))[(((3v_1 )/L))^2 +(−((3(√3)v_1 )/L))^2 ]=u^2   5v_1 ^2 −uv_1 =0  ⇒v_1 =(u/5)  ⇒ω_1 =((3u)/(5L))  at time t point A crosses the y−axis:  x_A =(L/2)cos (ω_1 t)=0  ⇒ω_1 t=((3ut)/(5L))=(π/2)   ⇒t=((5πL)/(6u)) ✓  y_A =v_1 t+(L/2) sin (ω_1 t)=((Lω_1 t)/3)+(L/2) sin (ω_1 t)       =(L/2)((π/3)+1) >L  ==================  θ_1 =ω_1 t=((3ut)/(5L))  x_1 =0  y_1 =v_1 t=((ut)/5)  x_A =x_1 +((L cos θ_1 )/2)=((L cos (((3ut)/(5L))))/2)  y_A =y_1 +((L sin θ_1 )/2)=((ut)/5)+((L sin (((3ut)/(5L))))/2)  θ_2 =(π/6)+ω_2 t=(π/6)−((3(√3)ut)/(5L))  x_2 =(L/4)−(((√3)L)/4)+u_2 t=(((1−(√3))L)/4)+(((√3)ut)/2)  y_2 =−(L/4)+v_2 t=−(L/4)+((3ut)/(10))  x_D =x_2 +((L cos θ_2 )/2)=(((1−(√3))L)/4)+(((√3)ut)/2)+((L cos ((π/6)−((3(√3)ut)/(5L))))/2)  y_D =y_2 +((L sin θ_2 )/2)=−(L/4)+((3ut)/(10))+((L sin ((π/6)−((3(√3)ut)/(5L))))/2)  ==================  following pictures are showing the  movement of the rods after the  collision as well as the locus of the  points A and D.

I1=I2=mL212mv1=JI1ω1=JL4ω1=3v1Lmu2=mucos30°u2=3u2mv2=musin30°Jv2=u2v1I2ω2=J×Lcos30°2ω2=33v1Lm2(v12+u22+v22)+12×mL212(ω12+ω22)=mu22v12+(3u2)2+(u2v1)2+L212[(3v1L)2+(33v1L)2]=u25v12uv1=0v1=u5ω1=3u5LattimetpointAcrossestheyaxis:xA=L2cos(ω1t)=0ω1t=3ut5L=π2t=5πL6uyA=v1t+L2sin(ω1t)=Lω1t3+L2sin(ω1t)=L2(π3+1)>L==================θ1=ω1t=3ut5Lx1=0y1=v1t=ut5xA=x1+Lcosθ12=Lcos(3ut5L)2yA=y1+Lsinθ12=ut5+Lsin(3ut5L)2θ2=π6+ω2t=π633ut5Lx2=L43L4+u2t=(13)L4+3ut2y2=L4+v2t=L4+3ut10xD=x2+Lcosθ22=(13)L4+3ut2+Lcos(π633ut5L)2yD=y2+Lsinθ22=L4+3ut10+Lsin(π633ut5L)2==================followingpicturesareshowingthemovementoftherodsafterthecollisionaswellasthelocusofthepointsAandD.

Commented by mr W last updated on 02/Jan/25

Commented by mr W last updated on 02/Jan/25

Commented by mr W last updated on 02/Jan/25

Commented by mr W last updated on 02/Jan/25

Commented by mr W last updated on 02/Jan/25

Commented by mr W last updated on 02/Jan/25

Commented by mr W last updated on 02/Jan/25

Commented by mr W last updated on 02/Jan/25

Commented by ajfour last updated on 02/Jan/25

beautiful omg! how you generate this.

beautifulomg!howyougeneratethis.

Commented by mr W last updated on 02/Jan/25

i just have used the app Grapher  like following.  (with m=ut in the equations)

ijusthaveusedtheappGrapherlikefollowing.(withm=utintheequations)

Commented by mr W last updated on 02/Jan/25

Commented by mr W last updated on 02/Jan/25

we can even generate an animation.  but since this app doesn′t support   animated gif images, so i just took  some screenshots for different  values of m.

wecanevengenerateananimation.butsincethisappdoesntsupportanimatedgifimages,soijusttooksomescreenshotsfordifferentvaluesofm.

Commented by MathematicalUser2357 last updated on 17/Feb/25

So I have a Grapher Free:

SoIhaveaGrapherFree:

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