Both magnitude and DIRECTION
For example,
• 12m East
• -2 miles
•9 meter north
• 8 miles up
The electromagnetic force<span> holds atoms and molecules together.
like a magnet's pull on steel.</span>
A sound wave<span> in a steel rail </span>has<span> a </span>frequency of<span> 620 </span>Hz<span> and a </span>wavelength<span> of 10.5 ... Find the </span>speed<span> of </span>a wave<span> with a </span>wavelength of 5<span> m and a </span>frequency of<span> 68 </span>Hz<span>.</span>
Answer:
not clear pic...but it's definitely not A)
Answer:
Approximately 
.
Assumption: the ball dropped with no initial velocity, and that the air resistance on this ball is negligible.
Explanation:
Assume the air resistance on the ball is negligible. Because of gravity, the ball should accelerate downwards at a constant 
near the surface of the earth.
For an object that is accelerating constantly,
,
where
is the initial velocity of the object,
is the final velocity of the object.
is its acceleration, and
is its displacement.
In this case, is the same as the change in the ball's height: 
. By assumption, this ball was dropped with no initial velocity. As a result, 
. Since the ball is accelerating due to gravity, 
.
.
In this case, would be the velocity of the ball just before it hits the ground. Solve for
.
.
