Q1) The graph shows how the amount of radiation emitted by a sample of the radionuclide
uranium 238 (U238) changes as time passes.
Radiation
emitted
(counts per 40
minute)
Time (billions of years)
(a)
What is the half-life of uranium 238 (U238)?
(You should show how you obtained your answer. You may do this on the graph
if you wish.)

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

What is the primary force that suspension bridges use cables to hold their spans up? a. tension force b. resistance force c. normal force d. elastic force e. applied force

Question 11 of 13 (1 point) jump to question: a stairway, ladder, or ramp must be present in excavations in which of the following situations? a. all trenches must have access/egress b. the trench is more than 15 feet wide but only 1 ½ feet deep c. the trench is more than 4 feet deep and the devices must be within 25 feet of all workers