Answer:
Approximately
.
Explanation:
This question suggests that the rotation of this object slows down "uniformly". Therefore, the angular acceleration of this object should be constant and smaller than zero.
This question does not provide any information about the time required for the rotation of this object to come to a stop. In linear motions with a constant acceleration, there's an SUVAT equation that does not involve time:
,
where
is the final velocity of the moving object,
is the initial velocity of the moving object,
is the (linear) acceleration of the moving object, and
is the (linear) displacement of the object while its velocity changed from
to
.
The angular analogue of that equation will be:
, where
and
are the initial and final angular velocity of the rotating object,
is the angular acceleration of the moving object, and
is the angular displacement of the object while its angular velocity changed from
to
.
For this object:
, whereas
.
The question is asking for an angular acceleration with the unit
. However, the angular displacement from the question is described with the number of revolutions. Convert that to radians:
.
Rearrange the equation
and solve for
:
.
Answer:
Option D: 1.5in in front of the target
Explanation:
The object distance is
.
Because the surface is flat, the radius of curvature is infinity .
The incident index is
and the transmitted index is
.
The single interface equation is 
Substituting the quantities given in the problem,

The image distance is then 
Therefore, the coin falls
in front of the target
Yes yes sir yes I’ll dm is the day I get that I wanna go home and get my
Average speed = (total distance covered) / (time to cover the distance)
Total distance = (80m) + (125m) + (45m) = 250 meters
Overall time = 10 minutes
Average speed = (250 meters) / (10 minutes)
<em>Average speed = 25 meters/minute </em>
Since we're only looking for average speed and not velocity, we don't care about any of the directions, and we don't need to calculate Mary's displacement.