(I) At room temperature, an oxygen molecule, with mass of 5.31 x 10⁻²⁶ kg, typically has a kinetic energy of about 6.21 x 10⁻²¹ J . How fast is it moving?

Block A has mass $20\mathrm{kg}$ and block B has mass $50\mathrm{kg}$. Starting from rest, the two blocks are pushed by identical forces through a distance of $10\mathrm{m}$. Which block (if either) is going faster at end of the $10\mathrm{m}$? Which block (if either) has the greatest kinetic energy at the end of the $10\mathrm{m}$?

What is the kinetic energy of a $500\mathrm{kg}$ car traveling at $27\mathrm{m}/\mathrm{s}$ (about $60\mathrm{mph}$)?

(c) Is it reasonable that a 30-kg child could run fast enough to have 100 J of kinetic energy?

A mother has four times the mass of her young son. Both are running with the same kinetic energy. What is the ratio v(son)/v(mother) of their speeds?

At what speed does a 1000 kg compact car have the same kinetic energy as a 20,000 kg truck going 25 km/h?

A 45 g bug is hovering in the air. A gust of wind exerts a force F (→ above F) = (4.0î-6.0ĵ) x 10¯² N on the bug. (b) What is the bug's speed at the end of this displacement? Assume that the speed is due entirely to the wind.

How much work does tension do to pull the mass from the bottom of the hill (θ = 0) to the top at constant speed? To answer this question, write an expression for the work done when the mass moves through a very small distance ds while it has angle θ, replace ds with an equivalent expression involving R and dθ , then integrate.