Answer:
Reference frame, also called frame of reference, in dynamics, system of graduated lines symbolically attached to a body that serve to describe the position of points relative to the body.
Answer:
E) True. The girl has a larger tangential acceleration than the boy.
Explanation:
In this exercise they do not ask us to say which statement is correct, for this we propose the solution to the problem.
Angular and linear quantities are related
v = w r
a = α r
the boy's radius is r₁ = 1.2m the girl's radius is r₂ = 1.8m
as the merry-go-round rotates at a constant angular velocity this is the same for both, but the tangential velocity is different
v₁ = w 1,2 (boy)
v₂ = w 1.8 (girl)
whereby
v₂> v₁
reviewing the claims we have
a₁ = α 1,2
a₂ = α 1.8
a₂> a₁
A) False. Tangential velocity is different from zero
B) False angular acceleration is the same for both
C) False. It is the opposite, according to the previous analysis
D) False. Angular acceleration is equal
E) True. You agree with the analysis above,
Answer:
i don't exactly know but im srry for not giving the right answer
Explanation:
Average speed = (total distance) / (total time)
First segment:
15 m/s for 10 sec; distance covered = (15 x 10) = 150 m
Second segment:
20 m/s for 20 sec; distance covered = (20 x 20) = 400 m
Third segment:
30 m/s for 15 sec; distrance covered = (30 x 15) = 450 m
Total time = (10s + 20s + 15s) = 45 sec
Total distance = (150m + 400m + 450m) = 1,000 m (1 km)
<em>Average speed</em> = (1,000 m) / (45 sec) = <em>22.22 m/s</em>
<h2>
Answer:</h2>
2.63 hours
<h2>
Explanation:</h2>
First we have to read carefully the problem, It start telling us that <u>Emily </u>was driving with average velocity of <em>87.5 km/h to the north</em>. Velocity is a physical variable that is definded in terms of :
- Speed of the object (<em>87.5 km/h</em>)
- Direction of the object (<em>north</em>)
Them the problem says that <u>Emily's trip has an average velocity of </u><u><em>76.8 km/h to the north </em></u>because she made a rest stop for 22 minutes<u><em>.</em></u>
Now you can ask yourself: If Emily was driving at <em>87.5 km/h, why the average speed of the trip was </em><u><em>76.8 km/h?</em></u>
we need to see how speed is defined:

<em>***Note 1: </em>
- Distance will be called as<em> "x" </em>and units will be kilometers(<em>km</em>)
- Time will be called as <em>"y" </em>and units will be hours(<em>h</em>)
So, 87.5 km/h would be the average speed for a distance "x" and a time "y" without stops. But Emily made a stop that took 22 minutes. For the same distance Emily's trip took more time and time is in the denominator. If our numerator is constant and our denominator gets higher, the final result will be lower
Now, we have the follow expressions:

***Note 2:
- we need to convert 22 <em>minutes</em> to <em>hours</em>. 1 <em>hour</em>= 60 <em>minutes</em>, so we need to apply the follow covert factor:

The problem aks us about how long does the trip take, it means that we have to find y.
We have two variables (x and y), and we have two equationts. We know that x have the same value for both problems (Because both average speeds have the same distance), so we can solve both equations for x and made equal each other


We have to expand (5) and then we have to solve for y
