Answer:
Renewable energy is important because, unlike nonrenewable energy, renewable energy sources replenish overtime.
Explanation:
Nonrenewable energy sources, such as fossil fuels, will eventually run out because they do not replenish in a reasonable amount of time. On the other hand, renewable energy sources, like windand solar power and biofuel, are unlimited or practically unlimited.
Answer:
Electrical force is directly proportional to the product of the charges on the two objects.
Explanation:
The electric force between two charges is given by :

Where
k is electrostatic constant
q₁ and q₂ are charges
d is the distance between charges
It can be very clear that the electric force is directly proportional to the product of charges and inversely proportional to the square of the distance between them.
Hence, the correct option is (a) "Electrical force is directly proportional to the product of the charges on the two objects".
Answer:
Explanation: RADIUS OF EARTH = 6400X1000m =
ACC DUE GRAVITY ABOVE SURFACE OF EARTH = g' =2.45 m/s^2
ACC DUE GRAVITY ON SURFACE OF EARTH =g= 9.8 m/s^2
A/C TO FORmULA
g'/g=1-2h/Re
g'/g +2h/Re = 1
2h/Re =1- g'/g
2h= (1- g'/g)Re
2h=(1-2.45 /9.8)
6400X1000
2h = (0.75)6400X1000
2h = 4800000
h= 2400000
m
Let F = the downstream speed of the water.
<span>Then the boat's upstream speed is: 15 - F </span>
<span>The boat's downstream speed is: 15 + F </span>
<span>Assume both the journeys mentioned take T hours, then using "speed x time = distance" we get: </span>
<span>Downstream journey: (15 + F)T = 140 </span>
<span>Upstream journey: (15 - F)T = 35 </span>
<span>Add the two formulae together: </span>
<span>(15 + F)T + (15 - F)T = 140 + 35 </span>
<span>15T + FT + 15T - FT = 175 </span>
<span>30T = 175 </span>
<span>T = 35/6 </span>
<span>Use one of the equations to find F: </span>
<span>(15 + F)T = 140 </span>
<span>15 + F = 140/T </span>
<span>F = 140/T - 15 </span>
<span>F = 140/(35/6) - 15 </span>
<span>F = 24 - 15 </span>
<span>F = 9 </span>
<span>i.e. the downstream speed of the water is 9 kph </span>
<span>Therefore, the boat's speed downstream is 15 + F = 15 + 9 = 24 kph.
the answer is: *24kph*</span>
I believe it’s the mass of the box but I don’t no if I’m right
Hope this helped