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:
#LearnwithBrainly
It's called a "Front"
Answer: It would be a front
b. the object slows down
c. the object changes direction
d. all of the above
Answer: Clouds are evaporated sea water. You should be asking "Why does the gravity on Earth pull us down and not evaporated water.
Explanation:
Answer:
Because of their mass
Explanation:
Clouds are made of water right ? so you are asking why they don't fall down if air is lighter than water .
The two biggest reasons the clouds stay in the sky are
1. Small Drops
2. Wind
Small drops of water fall more slowly than big drops, as the drops of the clouds fall thought the air, the air pushes back to them, because Small drops has less mass than large drops, clouds can only contain small drops of water.