Assuming north as positive direction, the initial and final velocities of the ball are:

(with negative sign since it is due south)

the time taken is

, so the average acceleration of the ball is given by

And the positive sign tells us the direction of the acceleration is north.
Answer:
option A
Explanation:
given,
distance between two masses is doubled
new distance, r' = 3 r
using gravitational force equation
............(1)
new gravitational force
now from the given condition
now, from equation (1)
now, the change in gravitational force factor is equal to
Hence, the correct answer is option A
Answer:
1. The nucleus is about 1/2 the size of the atom
Explanation:
Alpha particles are positive charge particles and they are bounced back by the nucleus because nucleus is also same size
Now in present experiment Rutherford found that very few alpha particles are bounced back along same path which shows that very small region inside the nucleus is having positive charge and rest part of the atom is empty.
Now if we found that half of the alpha particles are bounced back then it shows that size of the nucleus is very large now as compare to previous one because only nucleus can bounce back the alpha particles
so correct answer will be
1. The nucleus is about 1/2 the size of the atom
Early hypotheses were not based on observations.
Early hypotheses were not tested by experimentation.
Early hypotheses were formed from scientific questions.
Early hypotheses were influenced by creative thinking