Un mobil parcurge distanta dintre 2 localitati in 2 etape: in prima etapa parcurge d1+40km cu viteza v1=50km/h, apoi parcurge d2=60km cu v2=60km/h. Care este v medie?

Răspuns: 55 km / oră

Explicaţie:

Dat fiind :

Prima etapă de călătorie:

Distanța parcursă = d1 = 40km

Viteza (v1) = 50 km / oră

A doua etapă de călătorie:

Distanța parcursă = d2 = 60km

Viteza (v2) = 60km / hr

Viteza medie = (viteza primei etape + viteza celei de-a doua etape) / 2

Viteza medie = (50 + 60) km / h ÷ 2

Viteza medie = 110km / h ÷ 2

Viteza medie = 55 km / oră

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.

365.25 earth days are in the year of a light year