The fastest airplane is the lockheed sr 71 blackbird a high altitude spy plane first built in 1964. if an sr-71 is clocked traveling 15.0 km west in 15.3 s, what is its average velocity in kilometers per hours

For the motion of the plane it is given to us that it travel 15.0 km in 15.3 s

So here we can use the formula of average velocity to find it

formula is given as ratio of total displacement and total time

here it is given that

time = 15.3 s

we need to convert the time into hour as the speed is required in km/h

so we know that

now by the above formula

so the velocity of the plane would be 3529.4 km/h

the only real purpose of sputnik 1 was to beat the us into space. we were getting close to launching a useful satellite, explorer 1 - which launched on january 31, 1958. the ussr had to beat that, so they launched sputnik 1 on october 4, 19