1. A 274-N uniform ladder, 11.0 m long, rests against a smooth vertical wall. The coefficient of static friction between ladder and floor is 0.400. What minimum angle can the ladder make with the floor before it slips?

2. A 650-N billboard worker stands on a 4.00-m scaffold weighing 600 N and supported by vertical ropes at each end. How far would the worker stand from one of the supporting ropes to produce a tension of 660 N in that rope?

3. A bank vault is opened by applying a force of 140 N perpendicular to the plane of the door, 1.20 m from the hinges. Find the torque due to this force about an axis through the hinges.

A figure skater with arms initially extended starts spinning on the ice at 3 rad/s. She then pulls her arms in close to her body. Which of the following results?

a smaller angular momentum

a greater angular momentum

a greater rotational rate

a smaller rotational rate

A meterstick is supported by a knife-edge at the 50.0-cm mark. Doug hangs masses of 0.48 and 0.76 kg from the 10-cm and 80-cm marks, respectively. Where should Doug hang a third mass of 0.25 kg to keep the stick balanced?

6. An object of mass m and moment of inertia I has rotational kinetic energy KER. Its angular momentum is:

(2!)"/$

not given.

0.5 /.

(2!)"/$

please answer all the questions above.