Atomic and Nuclear Physics Answers

If a Saturn V rocket with an Apollo spacecraft attached had a combined mass of 3.1 × 10⁵ kg and reached a speed of 11 km/s, how much kinetic energy would it then have?

The displacement (in meters) of a particle executing simple harmonic motion at any instant of time is

given by, y = 0.2sin2π(350t − 0.30). Calculate i) the amplitude, ii) wave velocity, iii) wave length,

iv) frequency.

. The activity of a source was measured as follows

Time/days 0 2 3 4 5

Activity 137 63 44 31 22

The background count was 7

i. Explain background count. How does it occur?

ii. Sketch the above graph and determine the half life of the source.

Discuss Thomson’s atomic model ( what was his proposal on how an atom looks like?).

Explain its failures.

A metal rod of length 40.0 cm at 20°C is heated through a temperature of 45°C if the new length of the rod

is 40.05 cm calculate its linear expansivity

ACTIVITY 1.1. WRITE THE NUCLEAR REACTION INVOLVED IN THE SYNTHESIS OF EACH OF THE FOLLOWING NEW ELEMENTS.

A.Curium(Z=96) was formed by reacting Pu-239 with alpha particles ⁴²He,it has a half -life of 162 days.

B.Mendelevium(Z=101) was formed by reacting En-253 with alpha particles.

C.Meitnerium(Z=109) was formed by cold fusion which involves the combination on Bi and Fe nuclides at ordinary temperature.

The intrinsic temperature of a semiconductor is the temperatures at which the intrinsic

carrier concentration equals the impurity concentration. Find the intrinsic temperature for a

silicon sample doped with 1015 phosphorus atoms/cm3

.

Calculate the location of Ei in silicon at liquid nitrogen temperature (77 K), at room

temperature (300 K), and at 100 °C (let mp =1.0 m0 and mn= 0.19 m0). Is it reasonable to assume

that Ei is in the center of the forbidden gap?

Derive an expression for density of state for particle 3-D crystal having mass m with

energy ranging between E and E + dE

A spring stretches 14 cm when an object weighing 28 N is hung from it . what is the spring constant.