Compare your answer to the rms speed for helium atoms under the same conditions.

An object is solid throughout. When the object is completely submerged in ethyl alcohol, its apparent weight is 15.2 N. When completely submerged in water, its apparent weight is 13.7 N. What is the volume of the object?

A pressure as low as $1.00 \times 10^{-8}$ torr can be achieved using an oil diffusion pump. How many molecules are there in $1.00 \text{~cm}^3$ of gas at this pressure if its temperature is $300 \text{~K}$?

One mole of argon gas is confined to a $1.0\text{-liter}$ container at a pressure of $10 \text{~atm}$. What is the rms speed of the argon atoms?

A 75.0-kg man is riding an escalator in a shopping mall. The escalator moves the man at a constant velocity from ground level to the floor above, a vertical height of 4.60 m. What is the work done on the man by (a) the gravitational force and (b) the escalator?

A 47.0-g golf ball is driven from the tee with an initial speed of 52.0 m/s and rises to a height of 24.6 m. (a) Neglect air resistance and determine the kinetic energy of the ball at its highest point. (b) What is its speed when it is 8.0 m below its highest point?

A 75.0-kg skier rides a 2830-m-long lift to the top of a mountain. The lift makes an angle of

$$14.6 ^ { \circ }$$

with the horizontal. What is the change in the skier's gravitational potential energy?

Starting from rest, two skaters "push off" against each other on smooth level ice, where friction is negligible. One is a woman and one is a man. The woman moves away with a velocity of +2.5 m/s relative to the ice. The mass of the woman is 54 kg, and the mass of the man is 88 kg. Assuming that the speed of light is 3.0 m/s, so that the relativistic momentum must be used, find the recoil velocity of the man relative to the ice.

Ball A is thrown vertically upwards with a velocity of $v_0$. Ball B is thrown upwards from the same point with the same velocity t seconds later. Determine the elapsed time $t< \dfrac{v_0}{g}$ from the instant ball A is thrown to when the balls pass each other, and find the velocity of each ball at this instant.

A helium balloon is used to lift a load of $110 \text{~N}$. The weight of the envelope of the balloon is $50.0 \text{~N}$ and the volume of the helium when the balloon is fully inflated is $32.0 \text{~m}^3$. The temperature of the air is $0^{\circ} \text{C}$ and the atmospheric pressure is $1.00 \text{~atm}$. The balloon is inflated with a sufficient amount of helium gas that the net upward force on the balloon and its load is $30.0$ N. Neglect any effects due to the changes of temperature as the altitude changes. $(d)$ If the answer to Part $(c)$ is "Yes," what is the maximum altitude attained by the balloon?

At one instant of time, a car and a truck are traveling side by side in adjacent lanes of a highway. The car has a greater velocity than the truck has. Does the car necessarily have the greater acceleration?

A helium balloon is used to lift a load of $110 \text{~N}$. The weight of the envelope of the balloon is $50.0 \text{~N}$ and the volume of the helium when the balloon is fully inflated is $32.0 \text{~m}^3$. The temperature of the air is $0^{\circ} \text{C}$ and the atmospheric pressure is $1.00 \text{~atm}$. The balloon is inflated with a sufficient amount of helium gas that the net upward force on the balloon and its load is $30.0$ N. Neglect any effects due to the changes of temperature as the altitude changes. $(c)$ Does the balloon ever reach the altitude at which it is fully inflated?

A vector has a component of zero along the x axis of a certain axis system. Does this vector necessarily have a component of zero along the x axis of another (rotated) axis system?

Can three or more vectors with unequal magnitudes be added together so their sum is zero?