The final velocity of the rock before it touches the ground is 28 m/s.
Answer:
Explanation:
As the rock is thrown down, this means the acceleration due to gravity will be exerting on the rock. So the rock will be exhibiting a free fall motion. Thus, the acceleration of the rock will be equal to the magnitude of acceleration due to gravity. Then using the third equation of motion, we can determine the final velocity of the rock provided the values for initial velocity, displacement and acceleration is given in the problem itself.
So the acceleration is equal to 9.8 m/s² due to its free fall motion and displacement will be equal to the height of the tower which is given as 30 m. And the initial speed of the rock is stated as 14 m/s. The initial speed is represented as u, final speed is represented as v, displacement is represented as s and acceleration is represented as a.
Then, 2 × 9.8 × 30 = v²-(14)²
v²=784
v= 28 m/s
So the final velocity of the rock before it touches the ground is 28 m/s.
Answer:
The answer is 35.45 yds
Explanation:
You have to picture this to be able to understand it better (see attachment).
Start at the origin which is when the quarterback (QB) takes the ball. He runs backwards 12.1 yards, runs sideways for 19.8 yards (it doesn´t matter if he runs right or left), then he throws the ball forward 41.5 yards. If you look at the attachment, you can see I drew the path that the football followed. And then connected the dots from the origin and finish. The distance between those two points is the magnitude of the resultant displacement.
In order to calculate it, all you need to do is use the Pythagoream theorem, which says that the square of the hypotenuse equals the sum of the squares of the legs a and b of the triangle rectangle.
then solve for R
In this case, you know the length of leg a to be 19.8 yards which how much it moves sideways. And then, to get the length of leg b, all you need to do is substract how much it moved backwards from the 41.5yards forward displacement. This results in b leg being 29.4 yards long.
Now you have a triangle with:
- a = 19.8 yards
- b = 29.4 yards
Substituting this numbers in the equation:
- R = 35.45 yards
Answer:
Wave Variables
In the chapter on motion in two dimensions, we defined the following variables to describe harmonic motion:
Amplitude—maximum displacement from the equilibrium position of an object oscillating around such equilibrium position
Frequency—number of events per unit of time
Period—time it takes to complete one oscillation
For waves, these variables have the same basic meaning. However, it is helpful to word the definitions in a more specific way that applies directly to waves:
].
Explanation:
Answer:
Explanation:
a ) wave length of waves in water
= velocity / frequency
= 1482 / (18 x 1000)
= .0823 m
= 8.23 cm
b ) Applying Doppler's effect relation
frequency of reflected wave
= 18000 [ 1482 / (1482 - 4.95 ) ]
= 18000 x 1.003385
= 18061
Difference in frequency= 61 Hz
