The velocity vector v1 has a magnitude of 4.0 m/s and is directed along the +x-axis. the velocity vector v2 has a magnitude of 3.0 m/s. the sum of the two is v3, so that v3 = v1+v2. which of the following are true: a. the magnitude of v3 can be 7.0 m/s. b. the magnitude of v3 can be -5.0 m/s. c. the magnitude of v3 can be 3.0 m/s. d. the magnitude of v3 can be 0.0. e. the x-component of v3 can be 4.0 m/s. f. the magnitude of v3 can be 8.0 m/s

Use the empirical rule. the mean speed of a sample of vehicles along a stretch of highway is 70 miles per hour, with a standard deviation of 4 miles per hour. estimate the percent of vehicles whose speeds are between 66 miles per hour and 74 miles per hour. (assume the data set has a bell-shaped distribution.)

Alightning strike consists of charge moving from a cloud to the ground . in one particular case, the electrons in a lightning strike are confined to travel within a radius of 1.5 m and to move at a speed of 5.0 x 10 m/s. if the density of electrons in the strike is 10'15 electrons/m what current is carried by the lightning ?

Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 11.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.80 m/s; (b) he is then lifted at the constant speed of 4.80 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 78.0 kg rescue by the force lifting him during each stage