A thermal tap used in contain apparatus consist of a silica
rod, which fits inside at
aluminium tube whose internal
diameter is 8 mm out 0°c.
When the temperature is raised the
fit is no longer exact. Calculate
What change in temperature is necessary
to produce a channel whose cross-
Section is equal to that of a
tube of 1 mm internal
diameter.
Linear expansivity of stica = 8x10^-4 k^-1
Linear expansivity of Aluminium = 26x10^-4 k^-1

Ithink it’s: light bounce if off a mirror

Distance covered, s = 8ft - 4ft = 4 ftinitial velocity, u = 34 ft/sthe acrobat is moving upwards and therefore, a = -g = -9.81 m/s^2 = 32.19 ft/s^2applying equation of motion; s = ut -1/2gt^2then,4 = 34t -1/2*32.19t^24 = 34t - 16.095t^2rearranging; -16.095t^2 + 34t - 4 = 0solving the quadratic equation; t = {-34 +/- sqrt [34^2 - 4(-16.)]}/2(-16.095) = 1.06 +/- 0.93 = 0.13 or 1.99the acrobat will take 0.13 seconds to be at 8 ft above the ground. additionally, once at the maximum height, the acrobat will move down and be at the same spot (that is height) after 1.99 seconds moving down.