Q. An electric wire that has a mass of 5.0kg for a 20 m length is strung between two poles 20 m apart. What must be the tension in the wire if it is to take .80 seconds for a pulse to travel along the wire from one pole to the other?

Q. A small projectile is fired vertically downward into a fluid medium with an initial velocity as it enters the fluid medium of 60 m/s and after travelling x = 1 m the velocity of the projectile is reduced to 2.4 m/s. With the assumption that due to the resistance of the fluid the projectile experiences a retarding force proportional to (velocity) 3 , thus the deceleration is defined by the relation a = -kv3 m/s', where v is in m/s. Determine:
a) The value of k.
b) The velocity of the projectile 5 s after it is fired.
c) The position of the projectile 5 s after it is fired.