Batman drops his keys off a building that is 100 m tall, and they fall straight down.
He throws his grappling hook straight down 1 second after the keys fall to try to catch
them. The initial velocity of the keys is 0 m/s and the initial velocity of the grappling
hook is 10 m/s. When does the grappling hook catch the keys? (Assume that the
grappling hook is a simple projectile)
(a) Not before the keys hit the ground
(b) 5 m above the ground
(c) 35 m above the ground
(d) 10 m above the ground
(e) 25 m above the ground
