Answer:
The x represents the reference point on a motion map
Explanation:
-Motion maps are another way to represent the motion of an object. (other representations are graphical and mathematical models)
Answer: work Melvin did=9000J
Explanation:
Given to complete the question: If the sled moved 33.9m,how much work did Melvin do? Answer in unit of J and round to the nearest thousandth.
W = F ×S
W = 317 × cos 33°×33.9
W=9012.6055J
W=9000J to the nearest thousandth
New sound intensity level after the move is
10 log (1/3²)
= -20 log (3)
= -20 (0.4771) = 9.54 dB LOWER than before the move.
You can do this two ways:
1). Whatever kinetic energy the rolling ball has is the amount
of energy you have to absorb in order to stop it.
2). Whatever momentum the rolling ball has is the amount of
momentum you have to provide in the other direction to cancel it.
Since you asked about force and time, we sense 'impulse' in the
air, and we know that impulse is exactly a change in momentum.
So let's use #2 and talk about momentum and impulse.
Impulse = (force) x (time)
Momentum of a moving object is (mass) x (speed) .
-- Momentum of the first ball: (8 kg) x (0.2 m/s) = 1.6 kg-m/s
Impulse required to stop it = 1.6 kg-m/s
(force) x (10 sec) = 1.6
Force required = 1.6 / 10 = 0.16 Newton .
-- Momentum of the second ball: (4 kg) x (1 m/s) = 4 kg-m/s
Impulse required to stop it = 4 kg-m/s
(force) x (10 sec) = 4
Force required = 4 / 10 = 0.4 Newton .
You need more force o stop the second ball. Although its mass
is only 1/2 the mass of the 8kg ball, it's moving 5 times as fast,
and has 2.5 times the momentum of the bigger ball.
So you need 2.5 times as much impulse to stop it.
If you're going to push on each ball for the same length of time,
then you need to push 2.5 times as hard on the smaller ball in
order to stop it.
