Select the best answer for the question.
13. in a normally operating engine, intake and exhaust valves are opened by a cam and closed
o a. rocker arms or cam follower.
o b. lifters/tappets.
c. valve springs.
od. valve guides and/or pushrods.

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk

The sum of the normal stresses does not change as the stress state rotates through an angle. a)-trune b)- false

What is creep? what is stress relaxation?