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.
Intrusive igneous rocks cool down from magma slowly because they form underneath the surface, that will make them have large crystals.
Extrusive igneous rocks cool down from lava rapidly because they form at the surface, so that will make them have small crystals.
Answer:
20 Joules
Explanation:
Work is done whenever a force moves a body through a certain distance in the direction of the force. So, work done is the product of force and distance moved.
Therefore, we have;
Work done = Force x distance
i.e Wd = Fs
Given that: F = 20 N and s = 1 m, then;
Wd = 20 N x 1 m
= 20 Nm
The work done by the father is 20 Joules(Nm).
Im pretty sure the jet airplane is faster
