# Mass - 9th grade (14y) - math problems

Mass is a property of a physical body and a measure of its resistance to acceleration (a change in its state of motion) when a force is applied. An object's mass also determines the strength of its gravitational attraction to other bodies. The basic SI unit of mass is the kilogram (kg). Other are gram, tonne, milligram, etc.

#### Number of problems found: 185

• Mass The thickness of a metallic tube is 1cm and its outer radius is 11cm. Find the mass of such 1m long tube, if the density of the metal is 7.5g per cubic cm.
• Barrel of oil Barrel of oil weighs 283 kg. When it mold 26% oil, weighed 216 kg. What is the mass of the empty barrel?
• Brass tube The outer perimeter of brass tube (ρ = 8.5 g/cm3) is 38 cm. Its mass is 5 kg, length 54 cm. What is the pipe wall thickness?
• Heating plant Workers dump imported coke at heating plant. On the first day used half of the amount, the second day three quarters the rest and on the third day left 120 tons. How much coke they dump at heating plant?
• Electric cooker During which time t does an electric cooker with power input P = 500 W and with efficiency n = 75% heat water with mass m = 2 kg and temperature t1 = 10°C to the boiling point (t2 = 100°C). The specific heat capacity of water is c = 4 180 J. Kg-1. K-1
• Bracelet The silver bracelet weighs 62g and contains 59g of silver. What is the purity of the bracelet?
• Confectionery The village markets have 5 kinds of sweets, one weighs 31 grams. How many different ways a customer can buy 1.519 kg sweets.
• Butter fat A quarter of kg butter contains 82% fat. How many grams of fat are in four cubes of butter?
• Gold coin Gold coin contains 964 promile pure gold, which is 7.16 g. What is the weight of coin in grams?
• Mushrooms Mushrooms lose 90% by weight drying. How many fresh mushrooms are needed for 5 kg of dried mushrooms?
• Carrot seed Carrot seed germination is 85%, weight 1000 carrots seeds are 2.4g. How many seeds are likely to germinate if we sow 8g of seeds?
• Meat loses Meat loses 18% of its weight by smoking. How much raw meat butcher used to manufacture 35 kilos of smoked?
• Water percent A 15 g sample of the substance contains 70% water. After drying, the weight was reduced to 9 g. What percentage of water is now in the sample?
• Buoyancy force An adult male has a volume of about 0.070 m3. How much buoyancy does it affect him when he is completely immersed in water?
• A bottle A bottle full of cola weighs 1,320 g. If we drink three-tenths of it, it will weigh 1,008g. How much does an empty bottle weigh?
• Square Danov's father has a square of 65.25 milligram square of wire with a diagonal. How will the square be big when one mm weighs 7 mg?
• Apple variete This year, my uncle harvested 350 kg of apples, including 105 kilograms of Ontario, and the rest is Jonathan. Determine what percentage of the Jonathan apples.
• Father and son Father and son weigh together 108kg. The father weighs 2.6 times more than his son. How much does weight my father and son count?
• Boat A force of 300 kg (3000 N) is required to pull a boat up a ramp inclined at 14° with horizontal. How much does the boat weight?
• The gold coin The gold coin contains 900 per mille of pure gold. The coin weighs 950g. How much per mille is gold? How many grams are gold?

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