Question 2 The illustration shows all the forces in Newtons (N) acting on a box. 10 N 5N 8N 2N The sum of all the forces acting on the box results in a force acting on the box- to the right with a strength of 11 Newtons O to the left with a strength of 7 Newtons to the right with a strength of 25 Newtons 0 to the left with a strength of 6 Newtons

The protons in a nucleus are approximately 2 ✕ 10^−15 m apart. consider the case where the protons are a distance d = 1.93 ✕ 10^−15 m apart. calculate the magnitude of the electric force (in n) between two protons at this distance.

Athin electrical heater is inserted between a long circular rod and a concentric tube with inner and outer radii of 20 and 40 mm. the rod (a) has a thermal conductivity of ka = 0.15 w/(m*k), while the tube (b) has a thermal conductivity of kb = 0.8 w/(m*k) and its outer surface is subjected to convection with a fluid of temperature t= -15°c and heat transfer coefficient 60 w/(m2 *k). the thermal contact resistance between the cylinder surfaces and the heater is negligible. (a) determine the electrical power per unit length of the cylinders (w/m) that is required to maintain the outer surface of cylinder b at 15°c. (b) what is the temperature at the center of cylinder a?

10 pts. if an electromagnetic wave has a frequency of 8 ⋅ 10^14 h z , what is its wavelength? use λ=v/f. the speed of light is 3 ⋅ 10^8 m/s.