Box A, weighting 60 N, is placed on a table tilted at angle of 15˚. Another box, B, weighing 40N, is placed on top of A. Both boxes are at rest. A) Draw the free-body diagram for box B. What is the frictional force exerted on A by B? B) Draw the free-body diagram for box A. What is the frictional force exerted on A by the table?

A Frisbee flies across a field. Determine if the system has translational kinetic energy, rotational kinetic energy, neither, or both as determined by the observer in each of the following cases. a. The observer watches the flight of the Frisbee across the field from a park bench. b. The observer is a dog that runs directly beneath the Frisbee. c. The observer is an ant at rest on the Frisbee.

Show that when A+B=C then A2+B2+2ABcos , where is the angle between vectors A and B .

A force of F=(2.00i+3.00j) N is applied to an object that is pivoted about a fixed axle aligned along the z coordinate axis. The force is applied at the point r=(4.00i+5.00j)m. Find (a) the magnitude of the net torque about the z axis and (b) the direction of the torque vector .

A cam of mass M is in the shape of a circular disk of diameter 2R with an off-center circular hole of diameter R is mounted on a uniform cylindrical shaft whose diameter matches that of the hole (Fig. P1 3.78). a. What is the rotational inertia of the cam and shaft around the axis of the shaft? b. What is the rotational kinetic energy of the cam and shaft if the system rotates with angular speed around this axis?

A One end of a metal rod of weight Fg and length L presses against a corner between a wall and the floor (Fig. P14.64). A rope is attached to the other end of the rod. Find the magnitude of the tension in the rope if the angle between the rod and the rope is 90.

Sophia is playing with a set of wooden toys, rolling them offthe table and onto the floor. One of the toys is a small spherewith a mass of 0.024 kg and a radius of 0.020 m, and another isa small cylinder that also has a mass of 0.024 kg but a radius of0.013 m. She rolls each toy so that it has the same translationalspeed of 0.40 m/s. How much greater is the kinetic energy ofthe cylinder than the kinetic energy of the sphere?

Find the angle between vectors for (a) D=(-3.0i-4.0j)m and A=(-3.0i+4.0j)m and (b) D=(2.0i+4.0j+K)m and B=(-2.0i+3.0j+2.0K)m .

Scissors are like a double-lever "Stem, Which of the Simple machines in Figure 9.23 and Figure 9.24 is most analogous to scissors? Figure 9.23 A nail puller is a lever with a large mechanical advantage. The external forces on the nail puller are represented by solid arrows. The force that the nail puller applies to the nail ( Fo ) is not a force on the nail puller. The reaction force the nail exerts back on the puller ( Fn ) is an external force and is equal and opposite to Fo. The perpendicular lever arms of the input and output forces are li and l0 Figure 9.24 (a) In the case of the wheelbarrow, the output force or load is between the pivot and the input force. The pivot IS the wheel's axle. Here, the output force is greater than the input force. Thus, a wheelbarrow enables you to lift much heavier loads than you could with your body alone. (b) In the case of the shovel, the input force is between the pivot and the load, but the input lever arm is shorter than the output lever arm. The pivot is at the handle held by the right hand. Here, the output force (supporting the shovel's load) is less than the input force (from the hand nearest the load), because the Input is exerted closer to the pivot than is the output

(i) If you are trying to loosen a stubborn screw from a piece of wood with a screwdriver and fail, should you find a screwdriver for which the handle is (a) longer or (b) fatter? (ii) If you are trying to loosen a stubborn bolt from a piece of metal with a wrench and fail, should you find a wrench for which the handle is (a) longer or (b) fatter?