Wednesday

August 27, 2014

August 27, 2014

Posted by **Anonymous** on Friday, March 25, 2011 at 6:43pm.

h =

- physics -
**Damon**, Friday, March 25, 2011 at 7:06pmAc at top of loop = g = v^2/R

so

v^2 at top of loop must be g R

Height difference = (h-2R)

so total Ke at top of loop = m g (h-2R)

but

total Ke = (1/2)m v^2 + (1/2)I w^2

but v = w r so w = v/r

total Ke = (1/2) [m + I/r^2]v^2

but

v^2 must be gR

so

total Ke = (1/2)[m + I/r^2]gR

but we know total Ke is loss of Pe = m g (h-2R)

so

(h-2R) = (1/2)[ 1 + I/mr^2] R

h = 2R + (1/2)[ 1 + I/mr^2] R

I is (2/5) m r^2

so

h = 2R + (1/2) [ 7/5 ]R

h = 2.7 R

**Related Questions**

Physics - Height of ball launch - A solid ball of mass m and radius r rolls ...

Physics - A solid ball of mass m and radius r rolls without slipping through a ...

Physics - What is the minimum height you would have to place a solid ball of ...

Physics - A sphere with a moment of inertia 0.658mr2 and mass m and radius r ...

Physics - KE/rotation - In Figure 11-32 (which shows a ball at the top of an ...

AP Physics - A small solid marble of mass m and radius r will roll without ...

physics - A solid ball of radius b and mass m is released from the top of an ...

Physics (Rolling) - In Fig. 11-35, a solid brass ball of mass m will roll ...

Physics - A solid brass ball of mass 9.5 g will roll smoothly along a loop-the-...

Physics - KE - In Figure 11-32 (which shows a ball at the top of an incline, at...