Question

Ce distanta parcurge un automobil in 10 s daca el circula cu viteza de 72km/h.Cat timp ii trebuie automobilului pt a parcurge 25km

Answer 1

t=10 s
v=72 km/h= 72 * 1000/ 3600 m/s =72 * 10/36= 20 m/s

d=?

v=d/t rezulta d=v*t
d=20 m/s * 10 s= 30 m
Apoi urmatoarea intrebare poti sa o faci foarte usor cu regula de trei simplu:
25km=25000m

30m....................10s
25000m...............xs

30/25000=10/x
3/2500=10/x rezulta
3x=10*2500
x=25000/3
x=[aprox.] 8333,33 m

Answer 2

d=v*t=72000/3600m/s*10s=200m
v=20m/s
t=d/v=25000m/20m/s=1250s=20min50s