1. Suppose you have a metal bar. Its mass is 57.9g and its volume is 3cm'. What is its
density?

¡Hellow!

How we know, for calculate density, we can use the formule:

Where:

p = Density = ?

m = Mass = 57,9 g

v = Volume = 3 cm³

Let's replace according we information:

p = 57,9 g / 3 cm³

p = 19,3 g/cm³

The density of the metal bar is 19,3 g/cm³.

¿Good luck?

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s

80cm/s.

24cm/s.

53.3cm/s.