In January 2003, an 18-year-old student gained a bit of fame for surviving with only minor injuries-a remarkable traffic
accident. The vehicle he was driving was "clipped" by another one, left the road, and rolled several times. He was thrown
upward from the vehicle (he wasn't wearing a seat belt) and ended up dangling from an overhead telephone cable and a
ground wire about 8 meters above the ground. Rescuers got him down after 20 minutes. It is estimated that he reached a
maximum height of about 10 meters.
(a) Estimate the driver's vertical speed when he was thrown from the vehicle.
m/s
(b) If he had not landed in the wires, how fast would he have been going when he hit the ground?
m/s

It is given that the student reached a maximum height of 10 meters when he was thrown out. The initial speed with which he was throw is to be estimated.

Step 2:

The equation of motion connecting initial velocity, final velocity and distance is [tex]v^{2} = u^{2} + 2as[/tex] where v is the final velocity, u is the velocity with which he was thrown, a is acceleration due to gravity and s is the height.

The final velocity at the highest point 10 meters will be 0

s = 10 m

a = -10 m/[tex]s^{2}[/tex]

0 = [tex]u^{2}[/tex] + 2*(-10)*10

u = [tex]\sqrt{200}[/tex] = 14.14 m/s

Step 3:

The final speed when the student hits the ground will be the same as initial speed of the student when he was thrown out.

So the final speed of the student if he hit the ground would be 14.14 m/s

Step 4:

Answer:

The student's vertical speed when he was thrown out = 14.14 m/s

Speed of the student if he hit the ground = 14.14 m/s