Question

=
Gwen releases a rock at rest from the
top of a 50-m tower. If g = 9.8 m/s2 and
air resistance is negligible, what is the
speed of the rock as it hits the ground?
Select one:
o a. 784 m/s
O b. 31 m/s
O c. 56 m/s
d. 28 m/s​

Answer 1

Explanation:

Using expression

V2 -U2 =2gH

Here V= Final velocity (m/s)

U = Initial velocity (m/s)

H = Height

g = Acceleration due to gravity m/s2)

U= 0 m/s (Starts from rest)

V2 = 2x9.8x40

V= √784 m/s