Aglass marble is rubbed against a piece of silk. as a resultthe piece of fabric acquires extra electrons.

what happens to theglass marble?

a)the marble has lost the same number ofelectrons acquired by the piece of silk.

b)the marble acquires a positive charge andrepels the piece of silk.

c)the marble acquires a negative charge andattracts the piece of silk.

d)the marble has acquired the same numberof electrons acquired by the piece of silk.

e)the marble acquires a positive charge andattracts the piece of silk.

f)the marble acquires a negative charge andrepels the piece of silk.

the marble has lost the same number of electrons acquired by the piece of silk.  

the marble acquires a positive charge and attracts the piece of silk.

Explanation:

When an object or a material acquires extra electrons it becomes negatively charged while when it losses electrons it becomes positively charged. The glass marble was rubbed against the silk cloth, and the silk cloth acquires extra electron thereby becoming negatively charged, the same amount of charge the silk cloth acquires was lost from the glass marble thereby causing the marble to become positively charged. Also opposite charges attracts while likes charges repel and due to equal and opposite charge on silk and glass marble, they both will attract each other. thus option A and E is correct.

iron would move it is magnetic there is a mag field around the current in the wire

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.