The answer is the first one. That's because the general theory of relativity is the thing experiencing whatever is experiencing relative to something else. The second answer is just plain wrong. The third answer is just a constant, and doesn't relate to experiencing anything. And the fourth answer is a force between two objects, and it has no second comparison. The first answer is how a subject experiences two different things.
The bouncy ball experiences the greater momentum change.
To understand why, you need to remember that momentum is actually
a vector quantity ... it has a size AND it has a direction too.
The putty and the ball have the same mass, and you throw them
with the same speed. So, on the way from your hand to the wall,
they both have the same momentum.
Call it " M in the direction toward the wall ".
After they both hit the wall:
-- The putty has zero momentum.
Its momentum changed by an amount of M .
-- The ball has momentum of " M in the direction away from the wall ".
Its momentum changed by an amount of 2M .
Answer:
artificial: light bulb, flash light, computer screens. natural: sun, stars, fires.
The expression for the frictional force between the sled and the ground is:
where
is the coefficient of friction, m is the mass of the object and
is the gravitational acceleration.
The friction force in our problem is F=80.85 N. The mass of the object is m=15 kg. Re-arranging the formula, we can find the value of k:
