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:
the final kinetic energy is 0.9eV
Explanation:
To find the kinetic energy of the electron just after the collision with hydrogen atoms you take into account that the energy of the electron in the hydrogen atoms are given by the expression:
you can assume that the shot electron excites the electron of the hydrogen atom to the first excited state, that is
-10.2eV is the energy that the shot electron losses in the excitation of the electron of the hydrogen atom. Hence, the final kinetic energy of the shot electron after it has given -10.2eV of its energy is:
Answer:
Both balls hit the ground at the same time
Explanation:
Adam drops the ball from rest, so the ball just "<em>falls</em>" in vertical direction, being gravity its only acceleration, for cinematic movements we use that:
In this case we have that gravity is negative, and as Adam drops the ball,
Bob throws the ball horizontally, so the movement will be a <em>parabola</em>, we can divide into horizontal direction, and vertical direction.
But we only need to analize the vertical movement, in wich again the only acceleration is gravity, and compare it with Adam's ball. Again we have that gravity is negative, and as the initial throw is horizontal,
Finally, we have that
where
both for Adam's vertical drop, and for Bob's vertical component of the parabolic throw.
Now, if we put (the origin of the vertical coordinate), we get for both cases that
where we can clear the value for the time t, of the fall, wich will be the same in both cases.
Hence, both balls hit the ground at the same time.