Alnilam is the brightest star
Absolute brightness is how bright the star actually is. Apparent brightness is how bright the star looks.
Factors that influence how bright a star looks is distance. The fact that Alnilam has the same apparent brightness of the other two stars even though it is farther away, means that it is brighter.
Answer:
The only work done is when the person lifts the sack over a distance, W = 78.48 [N]
Explanation:
We have to remember the definition of work, which tells us that work is the result of a force by a distance, we must apply this concept in each of the movements of the person in the problem described.
W = F * d
where:
F = force [N]
d = distance [m]
The force is given by the producto of the mass by the gravity.
F = 5 * 9.81 = 49.05 [N]
W = 49.05 * 1.6 = 78.48 [N]
Answer:
The sled needed a distance of 92.22 m and a time of 1.40 s to stop.
Explanation:
The relationship between velocities and time is described by this equation:
, where
is the final velocity,
is the initial velocity,
the acceleration, and
is the time during such acceleration is applied.
Solving the equation for the time, and applying to the case:
, where
because the sled is totally stopped,
is the velocity of the sled before braking and,
is negative because the deceleration applied by the brakes.
In the other hand, the equation that describes the distance in term of velocities and acceleration:
, where
is the distance traveled,
is the initial velocity,
the time of the process and,
is the acceleration of the process.
Then for this case the relationship becomes:
.
<u>Note that the acceleration is negative because is a braking process.</u>
Answer: I would choose options C and D
Explanation:
It increases across a period but it decreases down a group.