b. How high did the arrow go?
c. How long is the arrow in the air?
a) The velocity of the arrow at its peak is zero
b) The maximum height of the arrow is 31.9 m
c) The time of flight is 5.10 s
Explanation:
a)
The motion of the arrow fired straight upward into the air is a uniformly accelerated motion, with constant acceleration (acceleration of gravity) towards the ground.
The initial velocity of the arrow when it is fired is upward: since the acceleration is downward, this means that as the arrow moves upward, its velocity decreases in magnitude.
Eventually, at some point, the velocity of the arrow will become zero, and then it will change direction (downward) and will start increasing in magnitude. The moment when the velocity raches zero corresponds to the peak of the trajectory of the arrow: therefore, at the peak the velocity is zero.
b)
Since the motion of the arrow is a uniformly accelerated motion, we can use the following suvat equation:
where
v is the final velocity
u is the initial velocity
a is the acceleration
s is the displacement
For the arrow, we have:
u = 25 m/s
v = 0 (when the arrow reaches the peak)
(negative because downward)
s is the maximum height reached by the arrow
And solving for s,
c)
In order to find the time it takes for the arrow to reach the maximum height, we use the following suvat equation:
where here we have:
v = 0 is the final velocity at the peak
u = 25 m/s
And solving for t,
This is the time the arrow takes to reach the top of the trajectory: therefore, the total time of flight is twice this value,
Learn more about accelerated motion:
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Answer: An increase or decrease in energy!
Explanation: I just took the quiz, I got it wrong with the increase or decrease of pressure. This is the right answer nowww.
Answer:
Approximately .
Explanation:
Consider one of the equations for constant acceleration ("SUVAT" equations)
,
where
Note that unlike other SUVAT equations, this one does not ask for the time required for the speed of the object to change from to . Since in this problem, time isn't given, this time-less equation would particular useful.
Here
Rearrange the equation to isolate the unknown, :
.
Make sure that all units are standard, so that the unit of the output will also be standard. Apply the equation:
.
Hence the final velocity will be approximately .