Aski gondola is connected to the top of a hill by a steel cable oflength 620 m and diameter 1.5 cm. as thegondola comes to the end of its run, it bumps into the terminal andsends a wave pulse along the cable. it is observed that it took14 s for the pulse to travel the length ofthe cable and then return.
(a) what is the speed of the pulse?
m/s
(b) what is the tension in the cable?
n

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".