Answer:
B is the best answer for this question
Explanation:
Let the speeds of father and son are
. The kinetic energies of father and son are
. The mass of father and son are 
(a) According to given conditions, 
And 
Kinetic energy of father is given by :
.............(1)
Kinetic energy of son is given by :
...........(2)
From equation (1), (2) we get :
..............(3)
If the speed of father is speed up by 1.5 m/s, so the ratio of kinetic energies is given by :


Using equation (3) in above equation, we get :

(b) Put the value of
in equation (3) as :

Hence, this is the required solution.
(1.9 yr) x (365.24 day/yr) x (86,400 sec/day) x (10⁹ nsec/sec)
= (1.9 x 365.24 x 86,400 x 10⁹) nanosec
= 6.00 x 10¹⁶ nanoseconds
Answer:
The students conclusion is wrong.
Explanation:
The students conclusion is wrong because liquids can not soak into concrete. The water evaporated because it was a hot sunny day. The water turned into a gas called water vapor.
Answer:
The distance between them, x = 5809.47 m
Explanation:
Given,
The average weight of a human, w = 600 N
The charge carried by the humans, q = 1.5 C
If 600 N of force acts between two opposite charges, the distance between the charges can be derived from the Coulomb's laws of force,
<em>
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Where,
= 9 x 10⁹ N m² C⁻²
Therefore
x² = 9 x 10⁹ X 1.5² / 600
= 33750000
x = 5809.46 m
Hence, the distance between the humans should be, x = 5809.47 m