Momentum of an object is defined as product of mass and velocity
so it is given as
here it is given that
mass = 0.15 kg
momentum = 6 kg m/s
so by plug in values in the above equation
so its speed will be 40 m/s
You watch distant Sally Homemaker driving nails into a front porch at a regular rate of 1 stroke per second. You hear the sound
1 answer:
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Answer:
You must add 8cm of water to the tank
Explanation:
In order to find how much the height is we will use the Snell Refraction law
.
This law relates the index of refraction of the water (n2), the index of refraction of the air (n1), the incidence angle relative to the vertical (theta1) and the refraction angle relative to the vertical (theta2) by using the next equation:
Then we will find the refraction angle relative to the vertical this way:
Then, theta2=32.12°
Now that we have this information we can imagine a triangle with a 30cm height and a 32.12° angle. This way we can find how much X is, this X will be the distance between the vertical line and the spot the beam hits the bottom, so we can use some trigonometry to find it, this way:
Then, X=18.8cm, we can approximate it to 19cm
Once we have X we will add 5cm to it which is how much the beam needs to be moved, then the new X will be 24cm
Now, with the new horizontal distance we will find the new vertical distance, let´s call it Y, this way we will know how much water we must add to move the beam, then we will have a triangle with a vertical distance called Y, the same 32.12° angle will be used as we are still working with the air-water interface and a 19cm horizontal distance, then:
Then, Y=38cm
In this case, you must add 8cm of water to the tank to move the beam on the bottom 5cm
Answer:
t = 12 s
Explanation:
To find the time in which the police reaches the thief you write the equation of motion of both thief and police:
The thief has a constant velocity, the position is then given by:
(1)
The police has an acceleration, then the position is:
(2)
the time in which the police reaches the thief is when their positions are equal, that is, when expression (1) equals expression (2). But before you calculate the acceleration of the police:
you replace this values in (2) and you equal the expression (1) and (2) (with vo = 0):
one root is t = 0s, but it is omitted because is the momment in which the thief pass in front of the police. The other root is:
hence, the time is 12 s