Some substances are radioactive. they may emit Alpha or Beta particles.
describe the characteristics of Alpha and Beta particles in terms of their:
- Structure
- penetration through air and other materials
-deflection in a electrical field.

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.

What is the measure of how much matter is in an object and that can be measured using a balance? a. height b. volume c. weight d. mass

Could we see a galaxy that is 20 billion light-years away?