A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity after 3.0 s, assuming no air?
A) 9.8 m/s upward
B) 9.8 m/s downward
C) 0 m/s
D) 19.6 m/s downward
Question 2
Dust particles are pulverized rock, which has density 2500 kg/m3. They are approximately spheres 20 m in diameter.
Treating dust as an ideal gas, what is the root-mean-square speed (thermal speed) of a dust particle at 400C? (The Boltzmann constant is 1.38 10-23 J/K.) A) 5.2 10-5 m/s
B) 1.7 10-5 m/s
C) 3.0 10-5 m/s
D) 7.3 10-5 m/s