Explain why this happens. Drag the terms on the left to the appropriate blanks on the right to complete the sentences. A. Angular speedB. L = wr/mC. L = mr/w2D. Ball, string and rodE. Radius F. Ball
1. Once the ball is going quickly and we don't hit it again, we can treat the___as being isolated.
2. We can treat the ball as a point mass at the end of the rope and write equation for the angular momentum of the ball:.
3. The angular momentum of the system is constant, somust increase asdecreases, and increasingmeans a shorter period.
In the playground game of tetherball, a ball tied to a rope circles a pole, wrapping the rope around the pole is it goes. Opponents compete to wrap the ball around the pole in one direction or the other; the game ends when the rope is entirely wrapped around the pole and the ball touches the pole. If you get the ball going around in one direction, as the rope shortens and the ball goes in smaller and smaller circles, the ball goes around with a shorter and shorter period.

For problems 1-3, consider a simple dc brush motor with a permanent magnet stator. with an an consider a simple dc brush motor with a permanent magnet ae supply voltage of 100 v, the no-load speed of the motor is 1000 rpm. this motor can provide a torque of 1.9 n-m at 800 rpm drawing a current of 2 a current are both zero at no load.) 1. with an armature supply voltage of 100 v, the motor is operated at 900 rpm. what is the motor torque? what is the mechanical power delivered by the motor? what is the current draw? what is the electrical power input? what is the energy efficiency of the motor? with an armature supply voltage of 100 v, the motor is operated at 1100 rpm (where it acts as a generator). what torque input is required? what mechanical power is required what current is generated? what is the electrical power generated? what is the energy efficiency of the motor acting as a generator? 2. with an armature supply voltage raised to 120 v, the motor is operated at 1000 rpm. what is the no-load speed? what is the motor torque? what is the mechanical power delivered by the motor? what is the current draw? what is the electrical power input what is the energy efficiency of the motor? 3.

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

Suppose you have a box. which of these is not necessarily a true statement regarding the relationship between the force applied to the box, the work done on the box, and the distance the box is moved? a. if the box is not moved, no force is being applied to the box. b. if no force is applied to the box, no work is done on the box. c. if work is done on the box, then a force is applied to the box. d. if work is done on the box, then the box is moved a distance.