A steel lift column in a service station is 4.0 m long and 0.20 m in diameter. Young's modulus for steel is 20 x 1010 N/m².
By how much does the column shrink when a 5000-kg truck is on it?
3.2 x 10⁻⁶ m.
7.8 x 10⁻⁶ m.
3.1 x 10⁻⁵ m.
8.0 x 10⁻⁷ m.
An aluminum wire 2.0 m in length and 2.0 mm in diameter supports a 10.0-kg mass. What is the elongation of the wire?
(The Young's modulus for an aluminum is 7.0 x 1010 N/m²).
0.22 mm.
0.89 mm.
0.11 mm.
0.33 mm.
Which of the following experimental results of the photoelectric effect can be explained by the classical or wave theory?
The instantaneous emission of electrons from a metal surface even with faint incident radiation
The kinetic energy of emitted electrons depending on frequency of incident radiation
Maximum speed of emitted electrons is independent of the intensity of the incident radiation
Number of photoelectrons emitted per unit time increases with light intensity
A wire of diameter 0.20 mm stretches by 0.20% when a 6.28N force is applied.
What is the elastic modulus of the wire?
1.0 x1012 N/m².
1.0 x 1011 N/m².
2.5 x 1010 N/m².
2.5 x 1012 N/m².
