8. Hope this helps.....a little
The answer is that it can involve changing the shape of matter, or changing the speed or direction of an object.
As you were holding the block down and in place, the spring exerted an upward force that balanced the downward push by your hand and its own weight. So this restoring force has a magnitude of <em>R</em> such that
<em>R</em> - 50 N - (3 kg) <em>g</em> = 0 => <em>R</em> = 79.4 N
As soon as you remove your hand, the block has acceleration <em>a</em> such that, by Newton's second law,
<em>R</em> - (3 kg) <em>g</em> = (3 kg) <em>a</em> => <em>a</em> = (79.4 N - (3 kg) <em>g</em>) / (3 kg) ≈ 16.7 m/s^2
pointing upward.
Answer:
23.4 m/s
Explanation:
f = actual frequency of the wave = 6.2 x 10⁹ Hz
= frequency observed as the ball approach the radar
= frequency observed as the ball recede away from the radar
V = speed of light
= speed of ball
B = beat frequency = 969 Hz
frequency observed as the ball approach the radar is given as
eq-1
frequency observed as the ball recede the radar is given as
eq-2
Beat frequency is given as

Using eq-2 and eq-1

inserting the values

= 23.4 m/s
Answer:

Explanation:
The electrostatic attraction between the nucleus and the electron is given by:
(1)
where
k is the Coulomb's constant
Ze is the charge of the nucleus
e is the charge of the electron
r is the distance between the electron and the nucleus
This electrostatic attraction provides the centripetal force that keeps the electron in circular motion, which is given by:
(2)
where
m is the mass of the electron
v is the speed of the electron
Combining the two equations (1) and (2), we find

And solving for v, we find an expression for the speed of the electron:
