An engine approaches a hill with a constant speed When it is

Last updated: 6/2/2023

An engine approaches a hill with a constant speed When it is at a distance of 0 9 km it blows a whistle whose echo is heard by the driver after 5 s If the speed of sound in air is 330 m s the speed of the engine is a 30 m sl c 32 mal b 60 m s