More crossword cr a p! :D (Science)
1 answer:
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Answer:
a). A conservative force permits a two-way conversion between kinetic and potential energies.
TRUE
Because there is no energy loss in presence of conservative forces so energy conversion in two ways are possible.
b). A potential energy function can be specified for a conservative force.
TRUE
negative gradient of potential energy is equal to conservative force
c). A non-conservative force permits a two-way conversion between kinetic and potential energies.
FALSE
here energy is lost against non-conservative forces
d). The work done by a conservative force depends on the path taken.
FALSE
work done by conservative force is independent of path
e). The work done by a non-conservative force depends on the path taken.
TRUE
work done by non conservative forces depends on path.
f). A potential energy function can be specified for a non-conservative force.
FALSE
It is not defined for non conservative forces
Answer:
1. Running velocity (5 m/s)
2. Resting velocity (0 m/s)
3. Walking velocity (-1 m/s)
1. Running speed (5 m/s)
2. Walking speed (1 m/s)
3. Resting speed (0 m/s)
Explanation:
Attached you will find the plot of position vs time of Ellie´s movement.
The velocity is the displacement of the object over time relative to the system of reference. The speed, in change, is the traveled distance over time in disregard of the system of reference.
So, the velocity is calculated as follows:
v = Δx / Δt
where
Δx = final position - initial position
Δt = elapsed time
1) The average velocity of Ellie while running is:
v = 1000 m - 0 m / 200 s = 5 m/s
While resting:
v = 0 m - 0 m / 100 s = 0 m/s
And while walking back:
v = 0 m - 1000 m / 1000 s = - 1 m/s
Note that in this last case, the initial position is 1000 m because Ellie is 1000 m from the origin of the system of reference when she walks back. The final position will be the origin of the system of reference, 0 m.
Comparing with the graphic, the velocity is the slope of the function position(t).
Then:
1. Running velocity (5 m/s)
2. Resting velocity (0 m/s)
3. Walking velocity (-1 m/s)
2) The speed is the distance traveled over time:
Running speed = 1000 m / 200 s = 5m /s
Resting speed = 0 m / 100 s = 0 m/s
Walking speed = 1000 m/ 1000 s = 1 m/s
Then:
1. Running speed (5 m/s)
2. Walking speed (1 m/s)
3. Resting speed (0 m/s)
