Dana has a sports medal suspended by a long ribbon from her rearview mirror. As she accelerates onto the highway, she notices  that the medal is hanging at an angle of 10° from the vertical. a. Does the medal lean toward or away from the windshield? Explain. b. What is her acceleration?

QC A bicycle is turned upside down while its owner repairs a flat tire. A friend spins the other A wheel and observes that drops of water fly off tan- gentially. She measures the heights reached by drops moving vertically (Fig. P7.8). A drop that breaks loose from the Figure P7.8 Problems 8 and 69. tire on one turn rises vertically 54.0 cm above the tangent point. A drop that breaks loose on the next turn rises 51.0 cm above the tan- gent point. The radius of the wheel is 0.381 m. (a) Why does the first drop rise higher than the second drop? (b) Neglecting air friction and using only the observed heights and the radius of the wheel, find the wheel's angular acceleration (assuming it to be constant).

A graduate student discovers that the only centrifuge in the laboratory is malfunctioning. The angular speed was supposed to be adjustable, but now it is stuck on a high angular speed, and the student is running an experiment that requires a low translational speed. Fortunately, the arm is adjustable. What can the student do to the length of the arm to get the correct translational speed?

The International Space Station (ISS) experiences an acceleration due to the Earths gravity of 8.83 m/s2. What is the orbital period of the ISS?

A jet fighter pilot knows he is able to withstand an acceleration of 9g before blacking out. The pilot points his plane vertically down while traveling at Mach 3 speed and intends to pull up in a circular maneuver before crashing into the ground. (a) Where does the maximum acceleration occur in the maneuver? (b) What is the minimum radius the pilot can take?

Anthony carelessly rolls his toy car off a 74.0-cm-high table. The car strikes the floor a horizontal distance of 97.0 cm from the edge of the table. a. What was the velocity with which the car left the table? b. What was the angle of the cars velocity with respect to the floor just prior to impact?

Starting from rest, a rectangular toy block with mass 300 g slides in 1.30 s all the way across a table 1.20 m in length that Zak has tilted at an angle of 42.0 to the horizontal. a. What is the magnitude of the acceleration of the toy block? b. What is the coefficient of kinetic friction between the block and the table? c. What are the magnitude and direction of the friction force acting on the block? d. What is the speed of the block when it is at the end of the table, having slid a distance of 1.20 m?

Your forehead can withstand a force of about 6.0 kN before fracturing, while your cheekbone can only withstand about 1.3 kN. a. If a 140 g baseball strikes your head at 30 m/s and stops in 0.0015 s, what is the magnitude of the ball’s acceleration? b. What is the magnitude of the force that stops the baseball? c. What force does the baseball apply to your head? Explain. d. Are you in danger of a fracture if the ball hits you in the forehead? In the cheek?

I need to find how far from the end of the ramp does the skateboard touch down?

We rest our calculator on a physics book; the surfaces have coefficients ?s = 0.45 and ?k = 0.25. a. To what angle do I need to tilt the book to make the calculator unstick and start sliding? b. Leaving our book ramp at this angle, what acceleration will the calculator experience?