Answer:
The distance the ball moves up the incline before reversing its direction is 3.2653 m.
The total time required for the ball to return to the child’s hand is 3.2654 s.
Explanation:
When the girl is moving up:
The final velocity (v) = 0 m/s
Initial velocity (u) = 4 m/s
a = -0.25g = -0.25*9.8 = -2.45 m/s². (Negative because it is in opposite of the velocity and also it deaccelerates while going up).
Let time be t to reach the top.
Using
v = u + a×t
0 = 4 - 2.45*t
t = 1.6327 s
Since, this is the same time the ball will come back. So,
<u>Total time to go and come back = 2* 1.6327 = 3.2654 s
</u>
To find the distance, using:
v² = u² + 2×a×s
0² = 4² + 2×(-2.45)×s
s = 3.2653 m
<u>Thus, the distance the ball moves up the incline before reversing its direction is 3.2653 m.</u>
Answer:
457.81 Hz
Explanation:
From the question, it is stated that it is a question under Doppler effect.
As a result, we use this form
fo = (c + vo) / (c - vs) × fs
fo = observed frequency by observer =?
c = speed of sound = 332 m/s
vo = velocity of observer relative to source = 45 m/s
vs = velocity of source relative to observer = - 46 m/s ( it is taking a negative sign because the velocity of the source is in opposite direction to the observer).
fs = frequency of sound wave by source = 459 Hz
By substituting the the values to the equation, we have
fo = (332 + 45) / (332 - (-46)) × 459
fo = (377/ 332 + 46) × 459
fo = (377/ 378) × 459
fo = 0.9974 × 459
fo = 457.81 Hz
Answer:

Explanation: Angular velocity is the number of revolutions made per unit time.
We convert the number of revolutions to radians and the time given in seconds to minutes,
Given;

Also,
60s = 1 min
hence

We now divide the number of revolution in radians by the time in minutes.

Answer:
The carrier lengthen is 0.08436 m.
Explanation:
Given that,
Length = 370 m
Initial temperature = 2.0°C
Final temperature = 21°C
We need to calculate the change temperature
Using formula of change of temperature



We need to calculate the carrier lengthen
Using formula of length

Put the value into the formula


Hence, The carrier lengthen is 0.08436 m.