In one hour are 60 minutes x 60 seconds. In that way is 1 ms (meter per second) 3.600 meters per hour or 3.6 kilometers per hour. 5.3 ms is 5.3 x 3.6 = 19.08 km/h.
initial velocity on xx=vi*cos(angle) 53.62 kmh 14.89 ms
7.1818
282.3 kmh
917.326 kmh
15 KMH = 9.32 MPH. The conversion is KMH x 0.6213333 = MPH.
50 kmh = 31.06856 mph
1001 kmh = 622 mph
336 kmh = 208.8 mph
90 kmh = 55.93 mph
105 MPH is about 170 KMH
574.8 kmh = 357.2 mph
186.4 MPH is 300 KMH.