Ameter stick a hurtles through space at a speed v = 0.25c relative to you, with its length aligned with the direction of motion. you stand on earth and have another meter stick b with its length aligned with the direction of motion of meter stick a. you measure the length of meter stick a to be 1 m. what is the length of meter stick b, l_b, as seen in the rest frame of meter stick a?

Plss anybody know how to do this? ? i need the answers from a through d

What is the primary force that suspension bridges use cables to hold their spans up? a. tension force b. resistance force c. normal force d. elastic force e. applied force

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.