The product of speed and time is distance. To calculate the total distance you multiple the speed in kilometers per second by the time at that speed in seconds, do this for all 3 different speeds then add them up, the 17.4 minutes eating does not affect the answer at all. to convert from minutes to seconds multiply time in minutes by 60, to convert from km/h to km/s divide km/h by 3600.
(23.5x60)x(74.5/3600) = 29.2km (rounded to 1 decimal place)
+
(15.9x60)x(111/3600) = 29.4km (rounded to 1 decimal place)
+
(49.2x60)x(38.7/3600) = 31.7km
=90.3km
The brackets are not necessary but i think it makes it more clear what is happening in your working.
Yes, plane accidents can happen near you, it can harm your property and cause a disaster.
ball drops 45m under g=10m/s/s
45=1/2x10xt^2 ... application of kinematic equaion from rest
90/10=t^2
t=3
24.0 m in 3 secs => 8m/s no air resistance
Decreases, stays the same, increases.
The volume decreases because as air is cooled, the individual molecules collectively possess less kinetic energy and the distances between them decrease, thus leading to a decrease in the volume they occupy at a certain pressure (please note that my answer only holds under constant pressure; air, as a gas, doesn't actually have a definite volume).
The mass stays the same because physical processes do not create or destroy matter. The law of conservation of mass is obeyed. You're only cooling the air, not adding more air molecules.
The density decreases because as the volume decreases and mass stays the same, you have the same mass occupying a smaller volume. Density is mass divided by volume, so as mass is held constant and volume decreases, density increases.
