Answer:
Explanation:
Given
height of grand canyon is 
Rock is dropped i.e. initial velocity is zero

Using Equation of motion

h=height
u=initial velocity
a=acceleration
t=time
here a=acceleration due to gravity


Answer:
Volcanic Eruptions
Explanation:
The volcano can start showing signs that it may be about to explode.
Answer:
Lithium and Sodium
Explanation:
Lithium and Sodium is in the same group 1A