Answer:
D
Explanation:
Because it is the principle of conservation of energy which is proved and verified
Answer:
461.88 N
Explanation:
= Weight of the swing = 800 N
= Tension force in the rope
= Horizontal force being applied by the partner
Using equilibrium of force in vertical direction using the force diagram, we get

Using equilibrium of force in horizontal direction using the force diagram, we get

Answer:
For an atom to have a balanced charged, the number of protons shall be equal to the number of electrons of an atom. proton is the positive part of an atom whereas electrons are the negative part of an atom. Only if the number of protons will be equal to the number of electron, the atom will be able to be neutral.
If the number of electron will be more, then the atom will be negative. If the number of electron will be less, then the atom will be positive.
<span>Answer:
skater x km/h
cyclist 20 faster x + 20 km/h
skater 30 km
cyclist 80 km
skater time = cyclist time
t=d/r
30 / x = 80 /( x + 20
cross multiply
30 ( x + 20 ) = 80 x
30 x + 600 = 80 x
30 x - 80 x = -600
-50 x = -600
/ -50
x = 12 km/h
12 km/h skater</span>