Answer:
The ball impact velocity i.e(velocity right before landing) is 6.359 m/s
Explanation:
This problem is related to parabolic motion and can be solved by the following equations:
----------------------(1)
---------(2)
----------------------- (3)
Where:
x = m is the horizontal distance travelled by the golf ball
is the golf ball's initial velocity
is the angle (it was a horizontal shot)
t is the time
y is the final height of the ball
is the initial height of the ball
g is the acceleration due gravity
V is the final velocity of the ball
Step 1: finding t
Let use the equation(2)
![t=\sqrt{\frac{2 y_{o}}{g}}](https://tex.z-dn.net/?f=t%3D%5Csqrt%7B%5Cfrac%7B2%20y_%7Bo%7D%7D%7Bg%7D%7D)
![t=\sqrt{\frac{2 (12.5 m)}{9.8 m/s^{2}}}](https://tex.z-dn.net/?f=t%3D%5Csqrt%7B%5Cfrac%7B2%20%2812.5%20m%29%7D%7B9.8%20m%2Fs%5E%7B2%7D%7D%7D)
s
Substituting (6) in (1):
-------------------(4)
Step 2: Finding
:
From equation(4)
![67.1 =V_{o}(1) 1.597](https://tex.z-dn.net/?f=67.1%20%3DV_%7Bo%7D%281%29%201.597)
![V_0 = \frac{6.71}{1.597}](https://tex.z-dn.net/?f=V_0%20%3D%20%5Cfrac%7B6.71%7D%7B1.597%7D)
m/s (8)
Substituting
in (3):
v =42 .01 - 15.3566
V=26.359 m/s
Here we apply conservation of linear momentum. The momentum of the truck with cargo and without cargo remains constant. That is,
.
Here
are initial mass and velocity.
are final mass and velocity. Here
and
.
The velocity of the truck be after its cargo is taken off is
![v'=\frac{mv}{m'} \\ v'=\frac{1800*10}{1500} \\ v'=12 m/s](https://tex.z-dn.net/?f=%20v%27%3D%5Cfrac%7Bmv%7D%7Bm%27%7D%20%5C%5C%20%20v%27%3D%5Cfrac%7B1800%2A10%7D%7B1500%7D%20%5C%5C%20%20v%27%3D12%20m%2Fs%20)
Answer:
A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.
Explanation:
In Physics, Doppler effect can be defined as the change in frequency of a wave with respect to an observer in motion and moving relative to the source of the wave.
Simply stated, Doppler effect is the change in wave frequency as a result of the relative motion existing between a wave source and its observer.
The term "Doppler effect" was named after an Austrian mathematician and physicist known as Christian Johann Doppler while studying the starlight in relation to the movement of stars.
<em>The phenomenon of Doppler effects is generally applicable to both sound and light. </em>
An example of the Doppler effect is a police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase. This is so because when a sound object moves towards you, its sound waves frequency increases, thereby causing a higher pitch. However, if the sound object is moving away from the observer, it's sound waves frequency decreases and thus resulting in a lower pitch.
<em>Other fields were the Doppler effects are applied are; astronomy, flow management, vibration measurement, radars, satellite communications etc. </em>
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Answer:
(a) P = 459.055 N.
(b) the refrigerator tips.
Explanation:
Given, the angle of ramp is 20°.
When the weight of refrigerator is resolved in directions parallel and perpendicular to ramp, 75×g×sin(20°) and 75×g×cos(20°).
⇒ normal contact force is 75×g×cos(20°).
⇒ frictional force is 0.3×75×g×cos(20°) = 207.414 N
so, total opposite force is 207.414 + 75×g×sin(20°) = 459.055 N.
so, the force needed is P = 459.055 N
And as the moment due to both opposite force and P force are in same direction the refrigerator tips rather than just sliding.