The correct answer is #4. They have the same number of protons but a different number of neutrons.
Answer:
2 meters towards the mirror.
Explanation:
In a plane mirror the image distance is equal to the object distance. Therefore, by moving 2 meters towards the mirror, the boy reduces the distance between him and the mirror to two meters which is the object distance. The image distance is also 2 meters. add the two distances you will get four meters.
Explanation:
Spring is stretched by force f to distance
"X"
now here by force balance we can say
f = kx
k = !
now here we will we say that energy stored in the spring will convert into kinetic energy
kx² = mv²
(x² = mv²
now solving above equation we will have
PART 2)
now for half of the extension again we can use energy conservation
ka²-k(x/2)² = 1 {mv²
¾fx=mv²
now the speed is given as
3 fr 4m V=
Beats are generated by two interfering waves when they have slightly different frequencies.
Mechanical Energy: 10.81 J given that
.
<h3>Explanation</h3>
The mechanical energy of an object is the sum of its kinetic and potential energy.
Kinetic Energy of this object:

Gravitational Potential Energy of this object:
.
.