Answer:
200 C
Explanation:
Let C1 and C2 be their charges. According to Coulomb's law

where k =
is the constant, R = 0.4m is the distance between them, F = 120 N is their resulting charge force


Since their total charge is 200C:
or 
We can substitute the above equation


or
So the larger charge is C = 200 C
As we know that in order to melt the copper we need to take the temperature of copper to its melting point
So here heat required to raise the temperature of copper is given as

We know that
melting temperature of copper = 1085 degree C
Specific heat capacity of copper = 385 J/kg C
now we have



now in order to melt the copper we know the heat required is

here we know that
L = 205 kJ/kg
now from above formula


now total heat required will be


As we know that

now we have

Answer:
60m
Explanation:
According to one of the equation of motions, v² = u²+2as where;
S is the distance
u is the initial velocity
v is the final velocity
a is the acceleration
Since the arrow is shot upwards, the body will experience a negative acceleration due to gravity i.e a = -g
Therefore our equation will become;
v² = u² - 2gS
Given u = 40m/s, g = 10m/s², S = 75m
Substituting to get the final velocity of the arrow we will have;
v² = 40²-2(10)(75)
v² = 1600 - 1500
v² = 100
v = √100
v = 10m/s
Total distance traveled is speed of the object × time taken
Total distance traveled = 10 × 6
= 60m
The arrow has therefore traveled 60m after 6seconds
Answer:
You now this question state why a person standing at point Y hears an echo