The rocket-driven sled Sonic Wind No. 2, used for investigating the physiological effects of large accelerations, runs on a straight, level track 1070 m (3500 ft) long. Starting from rest, it can reach a speed of 224 m>s1500 mi>h2 in 0.900 s. (a) Compute the acceleration in m>s 2 , assuming that it is constant. (b) What is the ratio of this acceleration to that of a freely falling body (g)? (c) What distance is covered in 0.900 s? (d) A magazine article states that at the end of a certain run, the speed of the sled decreased from 283 m>s 1632 mi>h2 to zero in 1.40 s and that during this time the magnitude of the acceleration was greater than 40g. Are these figures consistent?

Torque Torque = radius x perpendicular force Torques that will make things turn counterclockwise are positive, vice versa negative If a net torque exists, the object’s state of rotation will change Can have a net torque and net acceleration → object will both accelerate and change its rotation Forces can cause torques Forces ARE NOT torques...