A 300 Kg Tricycle Traveling At 40km/H Slows Down At 20km/H In 6s As It Approaches The Intersection. What Is The Force Applied On The Brakes Of The Tri

A 300 kg tricycle traveling at 40km/h slows down at 20km/h in 6s as it approaches the intersection. What is the force applied on the brakes of the tricycle? What is the impulse exerted on tge vehicle

 

Good Day

Problem:

A 300 kg tricycle traveling at 40km/h slows down at 20km/h in 6s as it approaches the intersection. What is the force applied on the brakes of the tricycle? What is the impulse exerted on tge vehicle

Answer:

Acceleration =  - 0.925 m/s² (decelerating)

force applied = - 277.5 N

Impulse =   - 1665 kg.m/s

Note:

1 hr = 3600 seconds

1 km = 1000 km

Given Data:

Vi (velocity initial) = 40 km/hr  or  11.11 m/s

40 km/hr  × 1000 m/1km × 1 hr/3600 s = 11.11 m/s

Vf (final velocity) = 20km/h or   5.56 m/s

20km/h × 1000 m/1km × 1 hr/3600 s = 5.56 m/s

t (time) = 6 s

a (acceleration) = ? unknown

Solution:

Solving for acceleration

a = (Vf-Vi)/t

  = 5.56 m/s - 11.11 m/s / 6 s

  = - 5.55 m/s / 6 s

  = - 0.925 m/s²

Solving for force applied

a (acceleration) =  - 0.925 m/s² (decelerating)

m (mass)   =  300 kg

F (force) = ? unknown

Solution:

F = ma

  = 300 kg × - 0.925 m/s²

 = - 277.5 kg.m/s² or  - 277.5 N (force is going opposite direction)

Solving for Impulse:

t (time) = 6 s

F (force) =  - 277.5 N

I (impulse) = ? unknown

Solution:

Impulse = F × t

             =  - 277.5 kg.m/s² × 6 s

             = - 1665 kg.m/s