Answer: 1.76 s
Explanation:
We have the following data:
is the total mass of the bike and the rider
is the initial velocity
is the force applied to the brakes
Firstly, we will find the acceleration 
with the following equation:
(1)
Isolating :
(2)
(3)
(4) This is the magnitude of the acceleration, however, since the final velocity is 0 m/s, this means the direction is negative
Hence:
(5)
On the other hand, with the following equation we can find the time 
:
(6)
Where:
is the final velocity (the bike stops)
Isolating :
(7)
(8)
Finally:
This iste time it takes to the bike to stop
Answer: 3.33 m/s
Explanation:
Assuming the questions is to convert 12 km/h to meter per second (m/s), let's begin:
In order to make the conversion, we have to know the following:
And:
Keeping this in mind, we can make the conversion:
Then:
Force = (mass) x (acceleration) (Newton's second law of motion)
Divide both sides of the equation by 'acceleration', and you have
Mass = (force) / (acceleration)
Mass = 17 newtons / 3.75 meters per second-sqrd = 4.533 kilograms (rounded)
Either convection or thermal energy
