Running on sand requires 1.6 times more energy spent than running on hard surface, so the force applied by our foot on sand is less.
Answer:
im sure your already past this but it's E.
Explanation:
This is because in this case potential energy is linear to height, which means that the higher the more potential energy.
There's no such thing as "an unbalanced force".
If all of the forces acting on an object all add up to zero, then we say that
<span>the group </span>of forces is balanced. When that happens, the group of forces
has the same effect on the object as if there were no forces on it at all.
An example:
Two people with exactly equal strength are having a tug-of-war. They pull
with equal force in opposite directions. Each person is sweating and straining,
grunting and groaning, and exerting tremendous force. But their forces add up
to zero, and the rope goes nowhere. The <u>group</u> of forces on the rope is balanced.
On the other hand, if one of the offensive linemen is pulling on one end of
the rope, and one of the cheerleaders is pulling on the other end, then their
forces don't add up to zero, because even though they're opposite, they're
not equal. The <u>group</u> of forces is <u>unbalanced</u>, and the rope moves.
A group of forces is either balanced or unbalanced. A single force isn't.
Answer:
Cosmic ray's frame of reference: 99,875 years
Stationary frame of reference: 501,891 years
Explanation:
First of all, we convert the distance from parsec into metres:
The speed of the cosmic ray is
where
is the speed of light. Substituting,
And so, the time taken to complete the journey in the cosmic's ray frame of reference (called proper time) is:
Converting into years,
Instead, the time elapsed in the stationary frame of reference is given by Lorentz transformation:
And substituting v = 0.98c, we find:
like dioxyribonucleic acid? if so then that's DNA
