Question

ListenA bicycle and its rider have a combined mass of 80. kilograms and a speed of 6.0 meters per second. What is the magnitude of the average force needed to bring the bicycle and its rider to a stop in 4.0 seconds?

a.1.2 × 102 N
b.3.2 × 102 N
c.4.8 × 102 N
d.1.9 × 103 N

Answer 1

a)
`1.2* 10^2\ N`

Step-by-step explanation:

t = Time taken

u = Initial velocity

v = Final velocity

a = Acceleration

`v=u+at\\\Rightarrow a=(v-u)/(t)\\\Rightarrow a=(0-6)/(4)\\\Rightarrow a=-1.5\ m/s^2`

The acceleration of the bicycle and rider is -1.5 m/s²

Force

`F=ma\\\Rightarrow F=80* -1.5\\\Rightarrow F=-120\ N=-1.2* 10^2\ N`

The magnitude of the average force needed to bring the bicycle and its rider to a stop is
`1.2* 10^2\ N`