A block of mass $M_1=0.640 \mathrm{~kg}$ is initially at rest on a cart of mass $M_2=0.320 \mathrm{~kg}$ with the cart initially at rest on a level air track. The coefficient of static friction between the block and the cart is $\mu_{\mathrm{s}}=0.620$, but there is essentially no friction between the air track and the cart. The cart is accelerated by a force of magnitude $F$ parallel to the air track. Estimate the maximum value of $F$ that allows the block to accelerate with the cart, without sliding on top of the cart.

A skydiver of mass $82.3 \mathrm{~kg}$ (including outfit and equipment) floats downward suspended from her parachute, having reached terminal speed. The drag coefficient is $0.533$, and the area of her parachute is $20.11 \mathrm{~m}^2$. The density of air is $1.14 \mathrm{~kg} / \mathrm{m}^3$. What is the air's drag force on her?

A bowling ball of mass $M_1=6.0 \mathrm{~kg}$ is initially at rest on the sloped side of a wedge of mass $M_2=9.0 \mathrm{~kg}$ that is on a frictionless horizontal floor. The side of the wedge is sloped at an angle of $\theta=36.9^{\circ}$ above the horizontal. a) With what magnitude of horizontal force should the wedge be pushed to keep the bowling ball at a constant height on the slope? b) What is the magnitude of the acceleration of the wedge, if no external force is applied? Section $4.7$

When a bus makes a sudden stop, passengers tend to jerk forward. Which of Newton's laws can explain this? a) Newton's First Law b) Newton's Second Law c) Newton's Third Law d) It cannot be explained by Newton's laws.

A large cubical block of ice of mass $M=64 \mathrm{~kg}$ and sides of length $L=0.40 \mathrm{~m}$ is held stationary on a frictionless ramp. The ramp is at an angle of $\theta=26^{\circ}$ above the horizontal. The ice cube is held in place by a rope of negligible mass and length $l=1.6 \mathrm{~m}$. The rope is attached to the surface of the ramp and to the upper edge of the ice cube, a distance $L$. above the surface of the ramp. Estimate the tension in the rope.

A rectangular block of width $w=116.5 \mathrm{~cm}$, depth $d=164.8 \mathrm{~cm}$, and height $h=105.1 \mathrm{~cm}$ is cut diagonally from one upper corner to the opposing lower corners so that a triangular surface is generated, as shown in the figure. A paperweight of mass $m=16.93 \mathrm{~kg}$ is sliding down the incline without friction. What is the magnitude of the acceleration that the paperweight experiences?