Answer:
v ’= v + v₀
a system can be another vehicle moving in the opposite direction.
Explanation:
In an inertial reference frame the speed of the vehicle is given by the Galileo transformational
v ’= v - v₀
where v 'is the speed with respect to the mobile system, which moves with constant speed, v is the speed with respect to the fixed system and vo is the speed of the mobile system.
The vehicle's speedometer measures the harvest of a fixed system on earth, in this system v decreases, for a system where v 'increases it has to be a system in which the mobile system moves in the negative direction of the x axis, whereby the transformation ratio is
v ’= v + v₀
Such a system can be another vehicle moving in the opposite direction.
Answer: Phillipe wins the race
Explanation:
Given
Length of track=20 m
Velocity of Phillippe=2 m/s w.r.t sidewalk
Velocity of sidewalk=1.5 m/s
Rena velocity=2 m/s
Therefore absolute velocity of P is 2+1.5=3.5 m/s
Time taken by phillippe 
=5.714+10=15.714 s
Time taken by rena

as the time taken by phillippe is less than rena therefore Phillippe wins the race.
OD because Boyle’s law specifically states