Recent content by malta

Homework Statement A motorist is traveling at l4m/s when he sees a deer in the road 48 m ahead. If the maximum negative acceleration of the vehicle is -7 m/s^2, what is the maximum reaction time At of the motorist that will allow him to avoid hitting the deer? Answer in units of s. What i did...

ok so F + mgcosx= N (friction)N= mgSinx So F = (mgSinx)/(friction) - mgCosx There we go, thanks again

oh haha yeah that makes sense, thanks for all your help man, I am trying to pull an all nighter here for physics. Thanks again

How would I go by eliminating either h or R? Also would you mind looking at my other post about static friction, its driving me nuts trying to figure it out Thanks for your help man

Oh ok yeah I am solving for Cosx=(R-h)/R So wouldn't the angle be arcCos of (R-h)/R?

anyone? I am doing a test review for a test tomorrow so this would greatly help me

Fore due to gravity is mgsinx and the frictional force = (coefficient of fiction)(mgCosx) And the condition on all forces along the plane so that the block doesn't move has to equal to zero But I can't seem to get what to set equal to what

Homework Statement If the coefficient os static friction between the incline and block is .3, then what is the minimum force,F, needed to prevent the block from sliding? m=20kg theta= 50 degrees Homework Equations Normal force= mgcosx Fs= uk mgcosx The Attempt at a Solution...

anyone?

Ok let's see now, so Cosx= a/g a= v^2/R So Cosx= a/g = v^2/ Rg = 2h/R Ok and Cosx=R-h/R So R-h/R = 2h/R thats what I could figure out, but i need to figure out the angle when it drops off the sphere

Yeah but with what? what can i substitute cosx with?

Alright, so since v^2 = 2gh you substitute and get Cosx= 2h/r. But how is theta a function of h??

Gotcha so it would only be mgcosx= mv^2/R? But what would i solve for?

Ok so this is independent of the mass of the penny and of g. So would i have mgcosx= mgh + mv^2/R??

I had a similar prob on mastering physics the other day, Since You know the masses. You know the final combined velocity. You know the initial speed of the block at rest. then the total momentum= (mass block + mass bullet)final velocity So the momentum of the block/bullet system is...