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:
1985kg
Explanation:
assuming that
pi =3.14
oil density = 950kg/ cubic meter
g= 9.8m/s
Let say the two train cars are of masses and
now if the speed of two cars are and
then we can say that the momentum of two cars before they collide is given by
here two cars are moving in opposite direction so we can say that the net momentum is subtraction of two cars momentum.
Now since in these two car motion there is no external force on them while they collide
So the momentum of two cars are always conserved.
hence we can say that the final momentum of two cars will be same after collision as it is before collision