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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: A) because forces are what stop and start motion
Explanation:
From Newton's first law, an object tends to stay in state of rest or motion unless acted upon by an unbalanced external force. This is also known law of inertia. This is because a force can stop or start a motion. A force cause body to accelerate to decelerate otherwise the body continues with constant speed.
Answer:
<em>The ball falls 0.3 m in the first 1/4 seconds, and it falls 0.92 m in the second 1/4 second</em>
Explanation:
<u>Horizontal Launch
</u>
When an object is thrown horizontally with a speed v from a height h, it describes a curved path ruled exclusively by gravity until it eventually hits the ground.
To calculate the vertical distance (y) traveled by the object in terms of the time (t) we use:

The fastball is thrown horizontally. The distance the ball falls in t=1/4 seconds = 0.25 seconds, is:


The distance the ball falls in t=1/2 seconds = 0.5 seconds is:


The distance it falls in the second 1/4 second is:


The ball falls 0.3 m in the first 1/4 seconds, and it falls 0.92 m in the second 1/4 second
Ans: C) Solid
Explanation: We will look into different states
A) Liquid : In liquid state molecules are not very tightly bound to each other. So, they have no fixed shape . They take the shape of container in which they are kept.
B) Gas : In gaseous state molecules are very loosely bound so they have very less intermolecular forces so they have much more freedom of movement.So, it will be also not correct.
D) Plasma : In Plasma state approximately equal amount of positive or negative charges are there, although its a type of hot ionized gaseous state but but due its different properties then other gases it is considered the 'fourth' state. And it also can't maintain it's definite shape and volume.So we will eliminate that also.
C) Solid : Finally we are left with solid state. Here molecules are tightly bound to each other . So, it doesn't change its shape and volume when kept in different container.
So 'Solid' state is the correct choice.
Hope it helps!!!