Newtons first law of motion or friction
Answer:
Speed of air = 1106.38 ft/s
Explanation:
Speed of sound in air with temperature

Here speed is in m/s and T is in celcius scale.
T = 50°F

Substituting

Now we need to convert m/s in to ft/s.
1 m = 3.28 ft
Substituting

Speed of air = 1106.38 ft/s
Average speed =
(total distance)/(total time)
Average speed = (99+90)/(2+3)
That's (189 km) / (5 hr)
Average speed = 37.8 km/hr
Atomic disguise makes helium look like hydrogen. ... A helium atom consists of a nucleus containing two positively charged protons and two neutrons, encircled by two orbiting electrons which carry a negative charge. A hydrogen atom has just one proton and one electron
Explanation:
The efficiency of a machine is 70% means 30% of the applied force is wasted in overcoming friction and 70% of the applied force is used to do the work