Answer:
217.43298 m/s
Explanation:
= Mass of bullet = 19 g
= Mass of bob = 1.3 kg
L = Length of pendulum = 2.3 m
= Angle of deflection = 60°
u = Velocity of bullet
Combined velocity of bullet and bob is given by

As the momentum is conserved

The speed of the bullet is 217.43298 m/s
I belive its like 1200 mile per hour ive done he math for it
Answer:

and

Explanation:
See attached figure.
E due to sphere
E due to particule
(1)
according to the law of gauss and superposition Law:
; electric field due to the small sphere with r1=R/4


then:
(2)
on the other hand, for the particule:

⇒
(3)
We replace (2) y (3) in (1):


--------------------
if R<x<2R AND 

remember that 
then:

solving:


but: R<x<2R
so : 
Let's call

the mass of the glider and

the total mass of the seven washers hanging from the string.
The net force on the system is given by the weight of the hanging washers:

For Newton's second law, this net force is equal to the product between the total mass of the system (which is

) and the acceleration a:

So, if we equalize the two equations, we get

and from this we can find the acceleration:
Answer:
B) how steep the slope is
Explanation:
Because you have to know how is the influence of the steep of the slope in the time that a ball reaches the bottom. The steep of the slope is the variable that you would have to change in an experiment.
I hope this is useful for you
regards