1.A 7 lb particle at rest is subjected to the action of its weight and forces F1= (2i+6j-2tk)lb, F2=(t^2i -4tj-1k) lb, and F3 =(-2ti) lb, where t is in seconds. the particle starts at the origin (0,0,0). determine the distance the ball is from the origin 4s after being released.
2.Each type of polymer has difference tensile behaviour, which one of the following types exhibits brittle nature at room temperature
a.Network
b.Linear
c.Elastomers
d.Linear and network
e.None of the above
3.A 25-mm diameter steel cylinder 300-mm long falls, because of its own weight, at a uniform rate of 0.1 m/s inside a tube of slightly larger diameter. A castor-oil film of constant thickness is between the cylinder and the tube. Determine the clearance between the tube and the cylinder. The temperature is 38 degrees Celsius. The specific gravity of steel=7.85