Suppose there are two twins, Greg and Sam. Greg stays on Earth and Sam travels to the stars as a scientist. Space travel has advanced to the point where spaceships can travel through the universe at speeds close to the speed of light. When Sam returns to Earth, how would the twins’ ages compare?

a. sam would be older
b. sam would be younger
c. sam and greg would be the same age

Crowbar of 5 metre is used to lift an object of 800 metre if the effort arm is 200cm calculate the force applied

What is required for an electric charge to flow through a wire? zero resistance in the wire a balance of electric potential high resistance in the wire a difference in electric potential

The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter, indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases, then goes through a maximum, and then decreases. consider an infinite wing with an naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9x10^6.