An air mass is a large pocket of air with a uniform temperature and humidity
Gravity is a non contact force , jump from a little high place (don't do that :P) , you wont just get stuck in the air you will fall down , this is gravity you dont need any contact
Answer:
F = 5
Explanation:
F = m x v^2/r = 2 x 10^2/5 =200/5 = 40 (N)
Three 40w lamp for 6 hours
