Answer:
C. It is radiation leftover from the Big Bang
Answer:
1/3 the distance from the fulcrum
Explanation:
On a balanced seesaw, the torques around the fulcrum calculated on one side and on another side must be equal. This means that:

where
W1 is the weight of the boy
d1 is its distance from the fulcrum
W2 is the weight of his partner
d2 is the distance of the partner from the fulcrum
In this problem, we know that the boy is three times as heavy as his partner, so

If we substitute this into the equation, we find:

and by simplifying:

which means that the boy sits at 1/3 the distance from the fulcrum.
Answer:
The speed of the block is 4.96 m/s.
Explanation:
Given that.
Mass of block = 1.00 kg
Spring constant = 500 N/m
Position 
Coefficient of friction = 0.350
(A). We need to calculate the speed the block has as it passes through equilibrium if the horizontal surface is friction less
Using formula of kinetic energy and potential energy

Put the value into the formula




Hence, The speed of the block is 4.96 m/s.
Answer:
C
Explanation:
only if there is a net force of zero, the body will not move
some people may say B but that is wrong because maybe one force is greater than the other so the object would still move even though the forces are in opposite directions and parallel