Search
2. A spring-mass system consisting of m = 2 kg and spring constant k = 50N/m is executing simple harmonic motion with amplitude of 0.9 m. (a) Calculate the total mechanical energy of the oscillator (b) What is the maximum velocity of the mass (c) For what value(s) of displacement will the oscillator have maximum kinetic energy ? (d) For what value(s) of displacement will the oscillator have maximum potential energy ? (e) If the oscillator is subjected to a mild damping force b= 0.07 kg/s find the time constant for the damped oscillator.
Find the sum of two vectors A=5m<60°and B=6m<130°
9. Chemical analysis shows that a bone fragment contains 10 g of C. Its activity is 50
counts/min. How old is the bone fragment?
8. A 2.71 g sample of KCl is found to be radioactive. It is decaying at a rate of 4490
Bq. The decay is traced to an isotope of potassium 40K, which constitutes 1.17% of
normal potassium. Calculate the half life of this nuclide.
7. The atomic ratio between Uranium isotope 238U and 234U in a mineral sample is found
to be 1.8 × 104
. The half-life of 234U is 2.5 × 105 yrs. Find the hal-life of 238U.
6. The polonium isotope 210
84 Po is unstable and emits a 5.30 MeV alpha particle. The
atomic mass of 210
84 Po is 20998 and that of 4
2He is 4.0026u. Identify the daughter nuclide
and find its atomic mass in u.
4. How much time is required for 5mg of 22Na (T
1
2 = 2.60 yrs) to reduce to 1 mg?
3. Show that the mass of radium (Mass number= 226, half-life = 1600 yrs) with an
activity of a curie (1Ci) is almost 1gm.
2. One (1) gram of aradioactive substance disintegrates at the rate of 3.7 × 1010 per
second. The atomic weight of the substance is 226. Calculate its mean life.
1. Using the Weiszacker’s formula, calculate the binding energy per nucleon for 235
92 U and
its two fission products: 149
60 Nd and 86
32Ge.
