Blocks a (5kg) and b (3kg) are released from rest on a 53 inclined surface and start sliding down the incline. before they released, the distance between the blocks is d. coefficient of kinetic friction between the block a and surface is 0.3. coefficient of kinetic friction between the block b and surface is 0.1. after 3s they are released, blocks collide and stuck together. 7.5p a) what is the initial distance, d, between the blocks? 7.5p b) what is the common velocity of the blocks after collision? 5p. c) how much mechanical energy is lost after collision? sin(53o)-0,8; cos(53°)-0.6 solution:

What is the role of the ocular lens?

Part f - example: finding two forces (part i) two dimensional dynamics often involves solving for two unknown quantities in two separate equations describing the total force. the block in (figure 1) has a mass m=10kg and is being pulled by a force f on a table with coefficient of static friction îľs=0.3. four forces act on it: the applied force f (directed î¸=30â above the horizontal). the force of gravity fg=mg (directly down, where g=9.8m/s2). the normal force n (directly up). the force of static friction fs (directly left, opposing any potential motion). if we want to find the size of the force necessary to just barely overcome static friction (in which case fs=îľsn), we use the condition that the sum of the forces in both directions must be 0. using some basic trigonometry, we can write this condition out for the forces in both the horizontal and vertical directions, respectively, as: fcosî¸â’îľsn=0 fsinî¸+nâ’mg=0 in order to find the magnitude of force f, we have to solve a system of two equations with both f and the normal force n unknown. use the methods we have learned to find an expression for f in terms of m, g, î¸, and îľs (no n).

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz. what wavelength is produced?