Answer:
Explanation:
Force, F = - mg j
r = - 7x i + y j
Torque is defined as the product f force and the perpendicular distance.
It is also defined as the cross product of force vector and the displacement vector.


[tex]\overrightarrow{\tau }= 7 m g x k
Here, we observe that the torque is independent of y coordinate.
Answer:
a)
Y0 = 0 m
Vy0 = 15 m/s
ay = -9.81 m/s^2
b) 7.71 m
c) 3.06 s
Explanation:
The knowns are that the initial vertical speed (at t = 0 s) is 15 m/s upwards. Also at that time the dolphin is coming out of the water, so its initial position is 0 m. And since we can safely assume this happens in Earth, the acceleration is the acceleration of gravity, which is 9.81 m/s^2 pointing downwards
Y(0) = 0 m
Vy(0) = 15 m/s
ay = -9.81 m/s^2 (negative because it points down)
Since acceleration is constant we can use the equation for uniformly accelerated movement:
Y(t) = Y0 + Vy0 * t + 1/2 * a * t^2
To find the highest point we do the first time derivative (this is the speed:
V(t) = Vy0 + a * t
We equate this to zero
0 = Vy0 + a * t
0 = 15 - 9.81 * t
15 = 9.81 * t
t = 0.654 s
At this time it will have a height of:
Y(0.654) = 0 + 15 * 0.654 - 1/2 * 9.81 * 0.654^2 = 7.71 m
The doplhin jumps and falls back into the water, when it falls again it position will be 0 again. So we can equate the position to zero to find how long it was in the air knowing that it started the jump at t = 0s.
0 = Y0 + Vy0 * t + 1/2 * a * t^2
0 = 0 + 15 * t - 1/2 * 9.81 t^2
0 = 15 * t - 4.9 * t^2
0 = t * (15 - 4.9 * t)
t1 = 0 This is the moment it jumped into the air
0 = 15 - 4.9 * t2
15 = 4.9 * t2
t2 = 3.06 s This is the moment when it falls again.
3.06 - 0 = 3.06 s
For the sound wave passing through regions of the ocean with varying density, longer wavelengths correspond to greater density of the water.
<h3>What is effect of density of a medium on wavelength of a wave?</h3>
The density of a medium is directly proportional to the wavelength of a wave.
The higher the density of the medium, the longer the wavelength of a wave.
Therefore, for a sound wave passing through regions of the ocean with varying density, longer wavelengths correspond to greater density of the water.
Learn more about density and wavelength at: brainly.com/question/9486264
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Answer:yes
Explanation: Rock can be weathered by ice, acids, animals, temp and etc because the breaking down or dissolving of rock and minerals on the earths surface.
rocks can be eroded by wind, water, ice and, gravity be cause of an action, and friction.
(I think going off of what i learned.)
Answer
This is done by Nuclear Fusion.
Light nuclei like Hydrogen(Deuterium) combine to produce new Elements like Helium.
²H + ²H === ⁴He + ENERGY
The subscripts of the Hydrogen atoms are 1
While that of Helium is 2. My Keyboard couldn't type those