Answer:
A. Two tennis balls that are near each other
Explanation:
The formula for gravitational force (F) between two objects is

where m₁ and m₂ are the masses of the two objects, d is the distance between their centres, and G is the gravitational constant.
Thus, two objects that are far from each other will have a smaller gravitational force. We can eliminate Options C and D.
If the objects are at the same distance, those with the smaller mass will have a smaller force.
The mass of a tennis ball is 57 g.
The mass of a soccer ball is 430 g.
Two tennis balls that are near each other will have a smaller gravitational attraction.
Answer:
The acceleration of the train is 5 m/s².
Explanation:
Given:
let the initial velocity of a train = 5 m/s and
final velocity of a train = 45 m/s
time taken = 8 s
To find:
acceleration: ?
Solution:
We define acceleration as change in velocity per unit time that is the difference between the final velocity and initial velocity divided by time.

On substituting the above values we get the required acceleration

Therefore,the acceleration of the train is 5 m/s².
After a thorough research, there exists the same question that has choices and the link of the graph (http://i37.servimg.com/u/f37/16/73/53/52/graph410.png)
<span>Choices:
A. 160 meters
B. 80 meters
C. 40 meters
D. 20 meters
E. 0 meters
</span>
The correct answer is letter E. 0 meters.
the answer is (a) molecules