Recent content by EddieHimself

Ok I have figured it out. You basically just have to separate out the effects of the shrinkage and the pressure and then add them all together.

Homework Statement So we have a compound cylinder, 100 mm internal diameter, 200 mm common diameter and an outer diameter of 300 mm. The pressure created by shrinking the outer cylinder on the inner cylinder is 30 MPa. If the maximum hoop stress on the outer cylinder is 110 MPa, what is the...

It's asking me to work out \ddot{\phi} (rad/s2), which is a different quantity to a\phi, (m/s2). If i just divide 21.49/1077 that equals 0.0199 which is not the right answer. My problem is that i don't know whether the value i have for a\phi is wrong, or whether I've done something wrong in the...

i've already done that bit. I worked out the normal acceleration for the loop, \dot{\theta} as 0.1437 rad/s, ar = 8.601 m/s2 and a\phi as 21.49 m/s2 but the problem is when i try to input all this into working out the values of \ddot{R} and \ddot{\phi} that i seem to come out with something...

You have to add in the acceleration towards the centre of the circle. That works out at \dot{\theta}2Rwhich is 12.572x0.1= 15.8. Then take the resultant of the 2 components, \sqrt{7.8952+15.82} = 17.66.

Homework Statement [PLAIN]http://a4.sphotos.ak.fbcdn.net/hphotos-ak-ash4/s720x720/300201_1919471514513_1473790586_31632884_1692676_n.jpg Homework Equations aR = \ddot{R} - R\dot{\phi}2 - R\dot{\theta}2cos2(\phi) a\theta = \frac{cos(\phi)}{R}\frac{d}{dt}(R2\dot{\theta}) -...

Ok I've sorted this one now; sodding the cos2(theta) division, i found that i could instead use the substitution sec2(a) = 1 + tan2(a) and then what resulted was 1500 = 5000tan(theta) -766.4tan2(theta) - 766.4 which rearranged to a simple quadratic, that being; 766.4tan2(theta) -...

Thanks for pointing that out, yes it was actually Cos2a and not Sin2a I just read it wrong, probably a bit tired lol. Ok thanks for your help.

1. OK so if you imagine a projectile is fired with an inital velocity (u) of 400 m/s at an angle theta. What two values of theta will cause the projectile to hit a point b that is 5 km horizontally away from the point of launch and 1.5 km vertically? u (magnitude)= 400 m/s deltaH = 1500 m (1.5...