Answer:

Explanation:
Given:
Mass of Piano: 99kg
Required:
Calculate its weight
The weight of an object is calculate as thus;

and 
The formula becomes



<em>Approximated</em>
<em />
<em>Hence, the weight of the piano is 970N</em>
Answer:
a ) = 381.48 J
b )= 84.25 cm
Explanation:
Kinetic energy of the runner
= 1/2 m v²
= .5 x 66 x 3.4²
= 381.48 J
The final kinetic energy of the runner is zero .
Loss of mechanical energy
= 381.48 J
This loss in mechanical energy is due to action of frictional force .
b )
Let s be the distance of slide
deceleration due to frictional force
= μmg/m
.7 x 66 x 9.8 / 66
a = - 6.86 m s⁻¹
v² = u² - 2 a s
0 = 3.4² - 2x6.86 s
s = 3.4² / 2x6.86
= .8425 m
84.25 cm
Hey there!
Your answer: shared electrons
There would usually be two forces that would make an atom stick together. It would be the positive, and negative of a electric charge. All this coming together would be the electromagnetic force. This is liked we talked about, both positive and negative charges attracted. And that would be the strong force. Which then gives our answer to be electrons.
Your answer: shared electrons
Answer:
E. Some charges in the region are positive, and some are negative.
Explanation:
Electric potential is given as;

where;
W is the work done in moving a charge between two points which have a difference in potential
Q is quantity of charge in the given region
If the electric potential at a given point in the region is zero, then sum of the charges in the given region must be equal to zero. For the charges to sum to zero, some will be positive while some will be negative,.
Therefore, the correct statement in the given options is "E"
E. Some charges in the region are positive, and some are negative.
Air pressure ''Decreases'' with Elevation. So B) would be your answer.