Question

va rog ajutor e urgent! problema 1.10.29 dau coroana

Answer 1

v1=30 km/h = 30*1000/3600=8.33 m/s

v2 = 10 m/s

dt=30 min = 30*60=1800 secunde

t = ?

d = ?

d=d0+v1*t=v1 *(t+dt)

d=d0+v2*t=v2*t

v2*t=(t+dt)*v1

v2*t=v1t+v1*dt

v2*t-v1t=dt*v1

t*(v2-v1)=dt*v1

t=dt*v1/(v2-v1)

t=1800*8.33/(10-8.33)=15000/1.667 = 9000 s = 9000/60 min = 150 min = 2 ore si jumatate

d = v2*t =10*9000=90000m=90 km

verificare

d=v1*(t+dt) = 8.333 (1800+9000) = 8.333*10800 = 90000 m = 90 km.