Q1. A truck travels beneath the airplane that is moving 125 km/h at an angle of 46 degrees to the ground. How fast must truck travel to stay beneath the airplane?

Q2. The distance from the point on the surface of Earth to a point on a surface of the moon is measured by aiming a laser light beam at the reflector on the surface of moon and measuring the time required for the light to make a round trip. The uncertainty in the measured distance Δx is linked to the uncertainty in the measured time Δt by Δx = 1/2 c Δt. The time intervals can be measured to ±0.90 ns.