Explanation:
It is known that opposite charges tend to attract each other whereas like charges tend to repel each other.
For example, when we rub a plastic pen with wool and it gets attracted towards an invisible tape then it means that there is an opposite charge present on both the objects.
A neutral object also tends to develop a charge when it comes in contact with a charged object.
Thus, we can conclude that the following statements are true.
- The tape might be positively charged.
- The tape might be uncharged.
there were different outcomes each time.
Speed = distance / time = 21 / 0.25 = 84 Km/hr
Answer:
d. Two soccer balls that are touching each other
Explanation:
Let 
be the mass of a tennis ball, 
is the mass of a soccer ball.
As the mass of a soccer ball is more than the mass of a tennis ball, so
Let 
be the distance between the centers of both the balls near each other and 
be the distance between the centers of both the balls touching each other.
So, 
The gravitational force, F, between the two objects having masses M and m and separated by distance d is
Where G is the universal gravitational constant.
As, the gravitational force is directly proportional to the product of both the masses and inversely proportional to the square of the distance between them, so selecting the larger mass (, soccer ball) separated by a lesser distance (, touching) to get more gravitational force.
Therefore, there will be a larger gravitational force between them when two soccer balls touching each other.
Hence, option (d) is correct.
A fluorescent light bulb is the most energy efficient in this group.
