Your friend drops your house keys down to you from their second floor window. if you catch them 2.4 m from where your friend dropped them, what is the velocity of the keys when you catch them?
a.
-6.9 m/s
c.
-7.2 m/s
b.
-6.5 m/s
d.
-7.4 m/s

Which statement best describes the superposition principle? a.) if two in-phase waves arrive simultaneously at a point, their amplitudes add up b.) if two out-of-phase waves arrive simultaneously at a point, their amplitudes add up c.) if two in-phase waves arrive at a point one after another, their amplitudes add up d.) if two out-of-phase waves arrive at a point one after another, their amplitudes adds up