Answer:

Explanation:
Where E is the magnitude of electric field...
k is called Columb's Constant. It has a value of 8.99 x 109 N m2/C2.
Qs is the magnitude of the source charge...
and r is the magnitude of distance between source and target...
(When electron comes to rest Δt the magnitude of Electric field E become zero momentarily but later achieves the maximum value...)
Answer:
The ratio of lengths of the two mathematical pendulums is 9:4.
Explanation:
It is given that,
The ratio of periods of two pendulums is 1.5
Let the lengths be L₁ and L₂.
The time period of a simple pendulum is given by :

or

Where
l is length of the pendulum

or
....(1)
ATQ,

Put in equation (1)

So, the ratio of lengths of the two mathematical pendulums is 9:4.
Is a solid...
when atoms or molecules or particles are in a fixed position it is a solid, it only vibrates in its place.
Answer: mass for Pyrex glass 84.21g
mass for sand 61.6g
mass for ethanol 41.32g
mass for water 62.07g
Explanation
By definition specific heat is the amount of heat required to change the temperature of 1 kg mas by 1°C
Q=mcΔT is formula for specific heat
Q is heat transfer
m is mass
ΔT is change in temperature
c is specific heat
c of Pyrex glass= 0.75 j/g°C
c of sand = 0.84 j/g°C
c of ethanol= 2.42 j/g°C
c of water = 4.18 j/g°C
now we will make M(mass) the subject, so equation becomes
m=Q/cΔT
for
pyrex glass T<em>f=</em>55.4°C
m=1920/(55.4-25)*0.75
m=84.21g {after cutting J(joules) and °C we are left with g(grams)}
for
sand T<em>f</em>=62.1°C
m=1920/(62.1-25)*0.84
m=61.6g {after cutting J(joules) and °C we are left with g(grams)}
for
ethanol T<em>f</em>=44.2°C
m=1920/(44.2-25)*2.42
m=41.32g {after cutting J(joules) and °C we are left with g(grams)}
for
water T<em>f=</em>32.4°
m=1920/(32.4-25)*4.18
m=62.07g {after cutting J(joules) and °C we are left with g(grams)}
i hope you understand the solution, thank you.