Answer:
a)
, b) 
Explanation:
a) According to the Principle of Energy Conservation, the kinetic energy of the box is transformed into elastic potential energy.

The spring constant is:

b) The initial speed needed to compress the spring by 1.5 centimeters is:


The directions of magnetic force and magnetic field lines are shown in the figure.
The direction to find out the magnetic field lines is given by right hand curl rule. If the thumb shows the direction of current, then the curling fingers show the direction of magnetic field lines.
The direction of force can be given by right hand thumb rule, where
Thumb - Direction of magnetic field lines
Forefinger - Magnetic
force
Centre finger -
Current
Such that forefinger, centre finger and thumb must be at 90 degrees to each other.
Answer:
B. The truck and mosquito exert the same size force on each other.
Explanation:
Newton's third law (law of action-reaction) states that
"When an object A exerts a force (action) on an object B, then object B exerts an equal and opposite force (reaction) on object A"
In this case, we can call
object A = the truck
object B = the mosquito
Thereforce according to Newton's third law, the force exerted by the truck on the mosquito is equal in magnitude to the force exerted by the mosquito on the truck (and in opposite direction).
The reason for which the mosquito will experience much more damage is the fact that the mosquito's mass is much smaller than the truck's mass, and since the acceleration is inversely proportional to the mass:

the mosquito will experience a much larger deceleration than the truck, therefore much more damage.
Ores are specifically defined as a type of rock wherein it contains essential. These minerals would then be extracted from the rock and would be used in various industries. One conventional way of overcoming the disadvantages of using ones is through the use of recycled aluminium products.