Answer:
they stay a solid
Explanation:
breaks apart do to whether such as erosion
The emerging velocity of the bullet is <u>71 m/s.</u>
The bullet of mass <em>m</em> moving with a velocity <em>u</em> has kinetic energy. When it pierces the block of wood, the block exerts a force of friction on the bullet. As the bullet passes through the block, work is done against the resistive forces exerted on the bullet by the block. This results in the reduction of the bullet's kinetic energy. The bullet has a speed <em>v</em> when it emerges from the block.
If the block exerts a resistive force <em>F</em> on the bullet and the thickness of the block is <em>x</em> then, the work done by the resistive force is given by,

This is equal to the change in the bullet's kinetic energy.

If the thickness of the block is reduced by one-half, the bullet emerges out with a velocity v<em>₁.</em>
Assuming the same resistive forces to act on the bullet,

Divide equation (2) by equation (1) and simplify for v<em>₁.</em>

Thus the speed of the bullet is 71 m/s
Answer:
accelerating
Explanation:
If we consider(v > u) Acceleration:
final velocity(v)= 14m/s
initial velocity(u)=10m/s
time taken(t)= 2 seconds
a=
=2m/s²
If we consider (v<u) Deceleration:
final velocity(v)= 3m/s
initial velocity(u)=9m/s
time taken(t)=2 seconds
a=
= -3m/s²
Answer:
c
Explanation:
Green house effect:
Temperature of atmosphere is going to increased continuously, because infrared light absorbed by gas .This increased in temperature atmosphere is called green house effect.
The green houses gases are as follows
,Carbon diaoxide,water vapor ,,Carbon diaoxide ,Methane ,,Carbon diaoxide oxide,CFCs ,ozone.
So the option c is correct.
Scientists use models to study atoms, Because atoms are very tiny, and almost impossible to cut open and look inside.. And the center of an atom is the nucleus and that is ever smaller.