Tension

See attached diagram A van accelerates downa hill going from rest to 32.8 m/s in 5.49 s. During the acceleration, a toy (m=0.115 kg) hangs by a string from the van's ceiling. The acceleration is such that the string remains perpendicular to the ceiling. How do you find the tension of the string?

Normal force

My problem is that I need to determine the normal force of the inlcine on the block. The coefficient of static friction between the block and incline is mu^s = .295. I have determiend that the minimum value of "F" is 18.49 N. I understand that "F" * sin (59.5) would be my answer to determine the normal force, yet I keep struggling on determining "F". Please help

Finding the radius of a circle

Please see the attachment. I do not have notes as to how to determine the radius, would you please walk me through the steps.

Problems

The coefficient of linear expansion of steel is 12 à— 10-6/C°. A railroad track is made of individual rails of steel 1.0 km in length. By what length would these rails change between a cold day when the temperature is -10 °C and a hot day at 30 °C? A 0.62 cm B 24 cm C 48 cm D 480 cm E 620 cm The coefficient of volumetric expansion for gold is 4.20 à— 10-5/C°. The density of gold is 19 300 kg/m3 at 0.0 °C. What is the density of gold at 1050 °C? A 20 200 kg/m3 B 19 300 kg/m3 C 19 000 kg/m3 D 18 800 kg/m3 E 18 500 kg/m3

Fundamentals of STATISTICAL AND THERMAL PHYSICS

(See attached file for full problem description)