Explanation: A sneaker is a want because you don't actually need it to survive
Answer:v=3.08 m/s
Explanation:
Given
mass of student 
distance moved 
Force applied 
acceleration of system during application of force is a

using 
where v=final velocity
u=initial velocity
a=acceleration
s=displacement



Answer:
20 J
Explanation:
Given:
Weight of the book is, 
Height or displacement of the book is, 
The work done on the book to raise it to a height of 2 m on a shelf is against gravity. The gravitational force acting on the book is equal to its weight. Now, in order to raise it, an equal amount of force must be applied in the opposite direction.
So, the force applied by me should be equal to weight of the body and in the upward direction. The displacement is also in the upward direction.
Now, work done by the applied force is equal to the product of force applied and displacement of book in the direction of the applied force.
Therefore, work done is given as:

Therefore, the work done to raise a book to a height 2 m from the floor is 20 J.
Answer:
Because the uncontrolled and unreasonable use of energy resources in the past few decades has led to the depletion of conventional type of resources. Although, measures are taken at the government levels to control the energy consumption, these attempts only meet with little success. Public awareness is the only way to successfully deal with this problem.
Explanation: