Can anyone help me ASAP with Physical Science homework? SI units and Volume.?

Question

1. The density of an object is 1000 mg/µm3. Calculate its density in SI.

2. A train is speeding with an acceleration of 0.18 km/h2. Calculate its acceleration in SI units.

3. A cubic container measuring 2 in x 2 in x 2in is filled with water.

a. What is the volume of this container in (in3)?
b. What is the volume of this container in (m3)?
c. What is the volume of this container in liters?
d. What is the mass of the water in kilograms?

I have worked on 22 of these problems, but I am stuck on these last 3 . Thank you in advance for any help you can provide with any of the questions. If you could provide a link to a website or a brief explanation (show work), I would greatly appreciate it. Thanks, again!

Answer 1

1. 1 mg = 1×10^-3 g = 1×10^-6 kg
1 μm = 1×10^-6 m
So 1000 mg/μm^3 = 1000 (10^-6) / (10^-6)^3 kg/m^3
= 10^-3 / 10^-18 kg/m^3
= 10^15 kg/m^3.

2. 1 h = 3600 s, 1 km = 1000 m.
So 0.18 km/h^2 = 0.18 (1000) / (3600)^2 m/s^2
= 1.4×10^-5 m/s^2.

3. (a) (2 in)^3 = 8 in^3
(b) 2 in = 5.08 cm = 0.0508 m, so the volume is
(0.0508 m)^3 = 1.31×10^-4 m^3
(c) 1 m^3 = 1000L, so the volume is 0.131 L.
(d) The density of water is 1 g/cm^3 = 1 kg/L, so the mass is 0.131 kg.

Answer 2

(1) The density = mass / Volume.
In SI units, mass is in Kg and volume is in m ³
Mass..........................= 1000mg / 10^6 Kg
Volume......................= μm³ / 10^18 m³
Hence Density .........= (1000/10^6) / (1 / 10^18)
...................................= (1000 x 10^18) / (10^6 x 1)
...................................= ( 1000 x 10^12)
...................................= 1 x 10^12 Kg/m³
...................................==================

(2) Acceleration = 0.18 km/h²
.............................= (0.18 x 1000) / (3600 x3600) m/s²
.............................= 13.9 x 10^-6 m/s²
............................===============

(3) Dimensions of the tank = 2 in x 2 in x 2 in
.....a. Vol = 8 in³
.....b. Vol = (2 x2.54/100)³ cubic metre
................= 1.311 x 10^-4 m³
................===============
.....c. Vol.= 1.311 x 10^-4 x 1000 litres
...............= .1311 litres
.......================
.....d. Mass of water = Volume x density
...................................= .1311 x 1 kg
..................................= 0.1311 Kg
..................................===========