What is the biggest challenge for space travel

A car moves along a circular track of radius 250 ft such that its seed for a short period of time 0<_ t <_ 4s, is v = 3 (t - t^2) ft/s, where t is in seconds. a. Determine the magnitude of its acceleration when t = 3s. b.

A paper clip is made of wire 0.75 mm in diameter. If the original material from which the wire is made is a rod 25 mm in diameter, calculate the longitudinal engineering and true strains that the wire has undergone during processing

Indicate whether the following statements are true or false for a reversible process: (A) Q=0. (B) Work may be calculated using the equation of state. (C) The total entropy change of the system and the surroundings is zero.

A 350 m^3 retention pond that holds rainwater from a shopping mall is empty at the beginning of a rainstorm. The flow rate out of the retention pond must be restricted to 320 L/min to prevent downstream flooding from a 6-hour storm.

What is the thermal energy contained within a cubic kilometre of granite (in barrels of oil equivalent) for every one degree change in temperature?

Work done by a system during a process can be considered as a property of the system. a) True b) False

When the compression process is non-quasi-equilibrium, the molecules before the piston face cannot escape fast enough, forming a high-pressure region in front of the piston. It takes more work to move the piston against this high-pressure region.

hypothetical A-B alloy of composition 40 wt% B-60 wt% A at some temperature is found to consist of mass fractions of 0.66 and 0.34 for the α and β phases, respectively.

10. Which of these requires a wheel alignment after replacement? A. Struts B. Shocks C. Both

What is the definition of diameter pitch?