The rotation of rod oa about o is defined by the relation θ= 0.5e^ -0.8t*sin3πt, where θ and t are expressed in radians and seconds, respectively. collar b slides along the rod so that its distance from o is r= 1 + 2t- 6t^2 + 8t^3, where r and t are expressed in feet and seconds, respectively. when t= 0.5 s, determine

(a) the velocity of the collar

(b) the acceleration of the collar

(c) the acceleration of the collar relative to the rod.

An electrical motor raises a 50kg load at a construct velencity .calculate the power of the motor, if it takes 40sec to raise the load through a height of 24m(take g =9.8n/g)

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

Ajournal bearing has a journal diameter of 3.250 in with a unilateral tolerance of 20.003 in. the bushing bore has a diameter of 3.256 in and a unilateral tolerance of 0.004 in. the bushing is 2.8 in long and supports a 700-lbf load. the journal speed is 900 rev/min. find the minimum oil film thickness and the maximum film pressure for both sae 20 and sae 20w-30 lubricants, for the tightest assembly if the operating film temperature is 160°f. a computer code is appropriate for solving this problem.