I'm going to assume that this gripping drama takes place on planet Earth, where the acceleration of gravity is 9.8 m/s². The solutions would be completely different if the same scenario were to play out in other places.
A ball is thrown upward with a speed of 40 m/s. Gravity decreases its upward speed (increases its downward speed) by 9.8 m/s every second.
So, the ball reaches its highest point after (40 m/s)/(9.8 m/s²) = <em>4.08 seconds</em>. At that point, it runs out of upward gas, and begins falling.
Just like so many other aspects of life, the downward fall is an exact "mirror image" of the upward trip. After another 4.08 seconds, the ball has returned to the height of the hand which flung it. In total, the ball is in the air for <em>8.16 seconds</em> up and down.
Answer:
b) directional
Explanation:
The prediction that alcohol slows reaction time is Directional . This is because for alcohol to be known as one which slows reaction time means there have been various hypothesis conducted which supports this.
In this case, formulation of a null hypothesis is usually necessary which means that alcohol does not slow reaction time and another alternative hypothesis that suggests that alcohol slows reaction time.
the International System of Units, the fundamental units are: The meter (symbol: m), used to measure length. The kilogram (symbol: kg), used to measure mass. The second (symbol: s), used to measure time. The ampere (symbol: A), used to measure electric current.
So, the time needed before you hear the splash is approximately <u>2.06 s</u>.
<h3>Introduction</h3>
Hi ! In this question, I will help you. This question uses two principles, namely the time for an object to fall freely and the time for sound to propagate through air. When moving in free fall, the time required can be calculated by the following equation:
With the following condition :
- t = interval of the time (s)
- h = height or any other displacement at vertical line (m)
- g = acceleration of the gravity (m/s²)
Meanwhile, for sound propagation (without sound reflection), time propagates is the same as the quotient of distance by time. Or it can be formulated by :
With the following condition :
- t = interval of the time (s)
- s = shift or displacement (m)
- v = velocity (m/s)
<h3>Problem Solving</h3>
We know that :
- h = height or any other displacement at vertical line = 19.6 m
- g = acceleration of the gravity = 9.8 m/s²
- v = velocity = 343 m/s
What was asked :
= ... s
Step by step :
- Find the time when the object falls freely until it hits the water. Save value as
- Find the time when the sound propagate through air. Save value as
- Find the total time
<h3>Conclusion</h3>
So, the time needed before you hear the splash is approximately 2.06 s.
Answer:
Explanation:
The momentum of the first piece = m v =- m x 31 i kg m/s in - x direction direction
The momentum of the second piece = -m x 31 j kg m /s in Y - direction
Total momentum = - 31 m( i + j )
To conserve momentum , the third piece must have momentum equal to this
and opposite to it
So momentum of the third piece = 3m x V = 31 m ( i +j )
V = 31/3 ( i + j ) =
Magnitude of velocity V = √2 x 31/ 3 = 14.6 m / s
Its direction will be towards the vector i + j ie 45° from x - axis in positive direction
