5.19 What is the torsional spring constant (torque per degree of angular deflection) in N • m∕ deg. for a solid round steel shaft 400 mm long if its diameter is (a) 30 mm? (b) 20 mm? (c) 30 mm for half its length and 20 mm for the other half?

J. j. thomson’s experiment disproved the theory that an atom

Avector of magnitude 2 cannot be added to a vector of magnitude 3 so that the magnitude of the resultant is a. zero b. 1 c. 3 d. 5 e. 7

Abatter hits a 0.140-kg baseball that was approaching him at 30 m/s and, as a result, the ball leaves the bat at 40 m/s in the reverse of its original direction. the ball remains in contact with the bat for 2.0 ms. what is the magnitude of the average force exerted by the bat on the ball?