PROBLEM 1.9
The material point moves along a circle of radius 1 m according to the equation s = 8t - 0.2t3.
Find the speed, tangential, normal and full acceleration at time 3 s.

Task 1.19
At what speed of movement will the relativistic contraction of the length of the moving body be 25%.

Task 1.29
A hydrogen molecule moving at a speed of 400 m / s, flies to the wall of the vessel at an angle of 60 ° and elastically hits it. Determine the momentum received by the wall. Take a mass of molecules equal to 3 • 10-27 kg.

Task 1.39
Find the momentum, total and kinetic energy of a neutron moving at a speed of 0.6 s.

Task 1.49
Up to what temperature it is possible to heat a sealed vessel containing 36 g of water so that it does not burst, if it is known that the walls of the vessel withstand a pressure of 5 • 106 Pa. The volume of the vessel is 5 liters.

Task 1.59
The coefficient of internal friction of oxygen under normal conditions is 1.9 • 10-4 kg / m • s. Determine the thermal conductivity of oxygen.

Task 1.69
Nitrogen with a mass of 20 g with isobaric heating was reported at 3116 J of heat. How has the temperature and internal energy of the gas changed.

Task 1.79
Determine the change in entropy, occurring when mixing 2 kg of water at a temperature of 300 K, and 4 kg of water at a temperature of 370 K.