An object executes circular motion with constant speed when- ever a net force of constant magnitude acts perpendicular the velocity. what happens to the speed if the force is not per- pendicular to the velocity? to "ems set. 7.2 rotational motion under constant angular acceleration 7.3 tangential velocity, tangential acceleration, and centripetal acceleration 5. a dentist's drill starts from rest. after 3.20 s of constant angu- lar acceleration, it turns at a rate of 2.51 x 10 rev/min. (a) find the drill's angular acceleration. (b) determine the angle (in radians) through which the drill rotates during this period. 6. va centrifuge in a medical laboratory rotates at an angu- lar velocity of 3600 rev/min. when switched off, it rotates through 50.0 revolutions before coming to rest. find the con- stant angular acceleration (in rad/s) of the centrifuge 7. a bicyclist starting at rest produces a constant angular accel- eration of 1.60 rad/s2 for wheels that are 38.0 cm in radius.

Which simple machine is not part of this compound machine? a. lever b. pulley c. inclined plane d. wheel and axle

In a thunderstorm, charge builds up on the water droplets or ice crystals in a cloud. thus, the charge can be considered to be distributed uniformly throughout the cloud. for the purposes of this problem, take the cloud to be a sphere of diameter 1.00 kilometer. the point of this problem is to estimate the maximum amount of charge that this cloud can contain, assuming that the charge builds up until the electric field at the surface of the cloud reaches the value at which the surrounding air breaks down. this breakdown means that the air becomes highly ionized, enabling it to conduct the charge from the cloud to the ground or another nearby cloud. the ionized air will then emit light due to the recombination of the electrons and atoms to form excited molecules that radiate light. in addition, the large current will heat up the air, resulting in its rapid expansion. these two phenomena account for the appearance of lightning and the sound of thunder. take the breakdown electric field of air to be eb=3.00ă—106n/c. part a estimate the total charge q on the cloud when the breakdown of the surrounding air is reached. express your answer numerically, to three significant figures, using ďµ0=8.85ă—10â’12c2/(nâ‹…m2) .

This is really important 1.which of the following prefixes represents the largest value? (2 points)gigahectorkilomilli2.which of the following types of graphs is best for plotting the mean, median, and mode of data? (2 points)bar graphbox-and-whiskercircle graphstem-and-leaf