Answer:

Given:
1$ = 4q
To Find:
How many quarters are in 20$
Explanation:
To find out how many quarters are in 20$ we need to multiple 4 × 20.



V = u + at
0 = u -9.8 x 5.5
u = 9.8 x 5.5 = 53.9 m/s
Answer:
The lowest energy of electron is the ground state.
Explanation:
Answer:
Explanation:
Given
length of window 
time Frame for which rock can be seen is 
Suppose h is height above which rock is dropped
Time taken to cover 
so using equation of motion

where y=displacement
u=initial velocity
a=acceleration
t=time
time taken to travel h is

Subtract 1 and 2 we get


and from equation 
so 

and 
so 



substitute the value of
in equation 2

