Physics 12 - CLOC Co Quizzes - Physics 12 - CL 70N Question 2 (1 point) Listen Three forces are acting on a 20kg mass as shown below: (assume North is up) 30N 30N 60N 20 kg What is the magnitude and direction of the mass's acceleration? 42.4 m/s² NW 2.1 m/s² NE 42.4m/s² NE 2.1m/s² NW 2.1m/s² SE Question 3 (1 point) Listen MacBook Pro ་

QUESTION 5 Two vechons gen brA-4i sj ant -3747 d nxa à gle bhent O 310 m) 145 a100 A bt (al 1 00 A a 2 QUESTIONG Comsider the fotowing mass distribution 4.00 kg at (D,01 4 00 kg at (0.350 and300 kg at 350.oy Where stould a fourth mns85ko be tced o thal the cte ma mass arrangement be at (0, 017 O 124m 165 m) O1200 m-2 80 m) O (124 m 105 m) O 2 Bl m 2 08 m)

Two uniform spheres with equal mass per unit volume are in contant with one another. The mass of sphere A is five times that if sphere B. The center of mass of the system is; a.)Inside sphere A somewhere on the line joing thr centers. b.)At the point where A and B touch. c.)Isside sphere B somewhere on the line joining the centers of A and B. d.)At the center of sphere A.  An apple can provide a person about 20 kJ of work. To what height can a 50 kg man climb upstairs if he eats one apple? ; a.)42.6 m b.)36.8 m  c.)40.8 m  d.)38.6 m

8. If we exert 1200N on an object to cause it to accelerate 0.55m/s2, what is the mass of the object?

Problem 1 Not So Simultaneous = The positions of two masses, ma and mb, are described by the equations: a(t) 3A sin (4wt) and xb (t) = 2A sin (3wt). (a) Not including t = 0, what are the first three times that the masses will pass through their respective equilibrium positions simultaneously? (b) Find the two expressions that would describe each mass' velocity. What were the velocities at the times you found in part a?

V h | "1470-24 g plates A particle of mass m is moving along the +x-axis with constant speed vo. At time t = 0 it enters a region between two plates which are separated by a distance h and lie in the x - z plane as shown in the figure. The figure is a side view of the plates with the +z axis pointing out of the screen. After entering the region between the plates, the particle is acted on by both gravity (which points in the -y direction and has magnitude g) and by a time varying force that points upward, in the +y direction, with magnitude F = bt, where b is a positive constant and is large enough that the particle does not touch the bottom plate. 1. Sketch the trajectory of the particle. 2. How long does it take for the particle to reach its lowest point? 3. If the particle is initially at the midpoint between the two plates, what is the minimum possible value of b such that the particle does not hit the lower plate? 4

02 Point material of mass 1 Kgr moves along the x-axis under the influence force F, which opposes the motion and is proportional to its square of speed with proportionality constant B=2. There is no gravity. A) Find the velocity and position of the material point for t > 0, if for t = 0 u = 2 m/s and x=0. B) Investigate your results: 1) if they satisfy the initial conditions, 2) if they have the right dimensions and 3) if in the limit t →∞ they logically give and expected results.

Three masses arranged as 6.00 [kg], 8.00 [kg]. What 25. y (m) shown on the right where ma mB = 4.00 |kg), and mc is the location of the center of mass? 4 A. (0.44 [m], 0.44 [m]) B. (2.67 [m], 2.67 [m]) 2 C. (2.44 [m], 2.89 [m]) Bo 1 D. (2.89 [m], 2.44 [m]) x (m) 2

1.Two ice skaters stand at rest in the center of an ice rink. Whenthey push off against one another the 45-kg skater acquires aspeed of 0.62 m/s. If the speed of the other skater is 0.89 m/s,what is this skater’s mass?Explain and labled the problem.

50. Find the center of mass of the sector of central angle 200 (sym- metric with respect to the y-axis) in Figure 5, assuming that the mass density is 8(x, y) = x². 200. FIGURE 5