Answer:
(a)

(b)
1120 N
Explanation:
Change in velocity,
is given by subtracting the initial velocity from the final velocity and expressed as 
Where v represent the velocity and subscripts f and i represent final and initial respectively. Since the ball finally comes to rest, its final velocity is zero. Substituting 0 for final velocity and the given figure of 8 m/s for initial velocity then the change in velocity is given by

To find
then we substitute 7 kg for m and -8 m/s for
therefore 
(b)
The impact force, F is given as the product of mass and acceleration. Here, acceleration is given by dividing the change in velocity by time ie

Substituting t with 0.05 s then 
Since F=ma then substituting m with 7 Kg we get that F=7*-160=-1120 N
Therefore, the impact force is equivalent to 1120 N
Answer:
charges of the beads is 1.173 ×
C
Explanation:
given data
mass = 3.8589 g = 0.003859 kg
spring length = 5 cm = 0.05 m
extend spring x = 1.5747 cm = 0.15747 m
spring's extension = 0.0116 m
to find out
charges of the beads
solution
we know that force is
force = mass × g
force = 0.003859 × 9.8
force = 0.03782 N
so we know force for mass
force = -kx
so k = force / x
put here force and x value
k = -0.03782 / 0.1575
k = -0.24 N/m
and
force for spring's extension
force = -kx
force = -0.24 ( 0.0116) = 0.002784 N
so here
total length L = 0.05 + 0.0116 = 0.0616
so charges of the beads = force × L² / ke
charges of the beads = 0.002784 × (0.0616)² / (9 ×
)
so charges of the beads = 1.173 ×
C
Answer:
The number of atoms are
.
Explanation:
Given that,
Diameter 

Distance = 2.60 cm
We calculate the number of atoms
Using formula of numbers of atoms


Hence, The number of atoms are
.