As we know by work energy theorem
total work done = change in kinetic energy
so here we can say that wok done on the box will be equal to the change in kinetic energy of the system

initial the box is at rest at position x = x1
so initial kinetic energy will be ZERO
at final position x = x2 final kinetic energy is given as

now work done is given as

so we can say

so above is the work done on the box to slide it from x1 to x2
Answer:

Explanation:
The impulse theorem states that the product between the force and the time interval of the collision is equal to the change in momentum:

where
F is the force
is the time interval
m is the mass
is the change in velocity
Here we have
m = 84 kg


So we can solve the equation to find the force:

Answer:A
Explanation:matter normally occurs in three phases;solid, liquid and gases. They may change from one phase to another due to temperature difference.
The molecules that makes up solids are held together by bonds. When heat is added,the molecules begin to move as a result,the bonds break and it turns to liquid.this process is called melting. The reverse of melting is freezing.
Liquid are made up of molecules that moves more freely than solids. When heat is added to liquid,the molecules gain more energy and begins to move faster. This causes them to turn to gases.
This process is called evaporation. It occurs at different temperature for different substances.
The particles of gases move more faster and are separated by large distances. A gas can change back to a liquid through condensation.
Answer:
Explanation:
Animal cells and plant cells share the common components of a nucleus, cytoplasm, mitochondria and a cell membrane. Plant cells have three extra components, a vacuole, chloroplast and a cell wall.
Answer:
Northern Lights ( Aurora Borealis)
Explanation:
When the electricaly charged sunspot gases (they are named a solar wind) escape the sun's chromosphere and penetrates from the earth magnetic sheild which is called earth's magnetosphere then upon there interaction with atoms and molecules of our atmosphere there are little bursts of photons in the form of light which made up these northern lights.