Density - practice problems - page 2 of 19
Why Does Density Matter?
1. Floating vs. Sinking:
- If an object’s density > liquid’s density → it sinks (e.g., iron in water).
- If density < liquid’s density → it floats (e.g., wood in water).
- *Example:* Ice ( ρ ≈ 0.92 g/cm³ ) floats on water ( ρ = 1 g/cm³ ).
2. Material Identification:
- Gold ( ρ = 19.3 g/cm³ ) vs. "fool’s gold" (pyrite, ρ = 5 g/cm³ ).
3. Engineering & Design:
- Ships are built with hollow shapes to reduce effective density.
- Lightweight materials (e.g., aluminum, ρ = 2.7 g/cm³ ) are used in aircraft.
Number of problems found: 377
- Approximately 83106
The castle courtyard, with an area of 100 m², is paved with oak cubes with an edge of 8 cm. Approximately 164 bricks were used to pave m². One dm³ of oak wood weighs 0.8 kg. Calculate the weight of all the bricks used to pave the courtyard. - Kilograms 83037
8 kg of butter is made from 20 hl of milk. How many kilograms of butter can be made from 450 l of milk? - Centimeter 83033
Calculate the weight in kg of a steel rope 1.5 cm in diameter and 10 m long if one cubic centimeter of steel weighs 7.8 g - Interpretation 83015
A cargo boat with a total weight of 4,500t sailed from the river to the sea. Calculate by how many tons it is possible to increase the weight of the cargo on the boat at sea so that the draft remains the same as in the river. The density of river water is
- Calculate 82808
Calculate the radius of an iron ball with a density of 7.8g/cm³ and a mass of 7kg. - A raft
I want to build a raft, and I have beams with a square section with side a=20cm and length l=2m, wood density 670 kg/m³. I will connect 10 beams - what is the volume of the raft and its weight? How deep will a raft sink in water (water density 1000kg/m³)? - Suspended 82617
A round steel weight (ρ1=7800 kg/m3) is suspended on a thread and immersed in water (ρ2=1000 kg/m3). The volume of the weight is 1dm³. With what force is the thread stretched? - Dimensions 82604
1 kg of cubed sugar consists of 840 cubes with an edge of 1.1 cm. Determine the sugar's density and the box's dimensions if the cubes are lined up in seven rows of nine cubes each. How many square meters of cardboard are needed to make 3000 boxes? - Horizontal 82601
Water flows in a horizontal tube at a speed of 2.24 m/s and has a pressure of 0.1 MPa. How fast does the water flow in the narrowed part of the tube if its pressure is 0.09 MPa?
- Harvested 82548
Farmers harvested 1110q of grain from 37 hectares of wheat. a) how many q of wheat did they harvest from 12 hectares? b) how many grains were harvested from 1 m². C) how big is the side of the square of the field from which they harvested 1q of wheat? - Completely 82545
A granite cube with an edge length of 1 dm and a weight of 2.5 kg is completely immersed in a container of water. How much buoyancy does it lighten? How much pressure does the cube exert on the bottom of the container? - Two-hundred-liter 82230
What is the weight of a two-hundred-liter barrel with ethanol if the empty barrel weighs 50 kg? - Diameter 82212
How many meters of copper wire with a diameter of d=3 mm will be produced from 60 kg of copper scrap if the specific gravity of copper is p=9g/cm³? - Semi-skimmed 82206
The dairy produces semi-skimmed milk (with 1.5% fat content) by skimming part of the fat from full-fat milk (with 4% fat content). 1 ton of semi-skimmed milk is produced from how many kilograms of fat milk?
- Calculate 82037
They will calculate the volume of a body that stretches the force gauge in the air with a force of 80N. After immersion in glycerol with a density of 12 kg. m-3 is a load cell stretched by a force of 30N. - Experimental 82019 3.6 tons of sugarcane were harvested on the experimental plot of 0.2 ha. How many tons of sugarcane can be harvested on a plot of land of 18.6 hectares with the same yield per hectare?
- Konečný 81976
Mr. Konečný used 0.9 kg of paint to paint an 8 m long and 1.2 m high fence. a) How many kg must he buy when he will paint a 35m long fence of the same height? b) How much paint will Mr. Malík need for a fence 1.5m high and 42m long. - Small density cube Calculate the mass of a cube with an edge of 15 cm made of oak wood with a density of ρ = 800 kg/m³.
- Calculate 81899
10 ml of mercury has been measured to weigh 0.135 kg. Calculate the density of mercury and compare it with the density shown in the tables.
The ring weighs 28g and has a volume of 2cm³ to find out if it is made of pure gold.Do you have homework that you need help solving? Ask a question, and we will try to solve it. Solving math problems.
