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A car waits at a ref light for a few seconds, and then accelerates straight ahead to 54km/h in 3.1s and then cruises at a constant speed for 75m. Find the total distance and time travelled

Respuesta :

bmountombudsma
1a) 
x1=vt 
x1=25*0.85=21.25 m 

1b) 
a=v/t 
a=25/3.5=2.2 m/s^2 
x=v^2/(2a)+x1 
x=625/4.4+21.25=163.3 m 

c) 
a=v/t 
a=25/3.5=2.2 m/s^2 

2) 
a=v/t=15/3.1=4.8 m/s^2 
x1=v^2/(2a) 
x1=225/9.6=23.4 m (while accelerating) 
x2=vt=15*4500=67,500 m 
total distance is 
x=x1+x2=23.4+67,500=67,523.4 m =67.523 km