Falling objects drop with an average acceleration of 9.8 m/s2. An arrow is shot with a velocity of 11.76 m/s straight down from the top of a tall castle hitting an armored knight with a downward velocity of 49 m/s. How long was the arrow in flight?

3.8 secs

Explanation:

Parameters given:

Acceleration due to gravity, g = 9.8

Initial velocity, u = 11.76 m/s

Final velocity, v = 49 m/s

Using one of Newton's equations of linear motion, we have that:

where t = time of flight of arrow

The sign is positive because the arrow is moving downward, in the same direction as gravitational force.

Therefore:

The arrow was in flight for 3.8 secs

the current is 0.6

voltage ÷ resistance = current

so 12 ÷ 20 = 0.6