Mass - practice for 14 year olds - page 9 of 22
Number of problems found: 437
- Bracelet
The silver bracelet weighs 62g and contains 59g of silver. What is the purity of the bracelet? - Contains 36193
The silver bracelet with a purity of 925 per mille contains 25.9 g of silver. What is the weight of the bracelet? - Hydraulic 36021
The small piston of the hydraulic jack has a capacity of 40 cm² and a large 120 cm². How heavy will a body lift when a man weighing 70 kg stands on a small piston? - Electric cooker
During which time, 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 - Hydraulic 35301
The hydraulic jack has pistons with a capacity of 6 cm² and 360 cm². How much force do we have to apply to the smaller piston to be able to lift a body weighing 180 kg on the larger piston? - Vacation 35133
The family is going on vacation. Everyone has their luggage. Together the luggage weighs 21kg. The mother's luggage weighs two times more than the father's and the son's 4 kilograms less than the mother's. How much does luggage weigh? - Efficiency 35023
The cellar, which has a floor area of 50 m2, 3 m below ambient level, was flooded with water to a height of 80 cm. How long does it take for a pump with a power input of 1 kW and an efficiency of 75% (η = 0.75) to drain the water? - Percentage 34761
The company's new management has announced that mass layoffs will be necessary due to the poor financial situation. It is estimated that the work that 5 employees did will have to be done by 3 employees. What percentage of the company's employees would lo - Bananas and mango
5 kg of bananas and three kilograms of mango cost 146 CZK, and two kilograms of bananas and 5 kilograms of mango cost 142 CZK. How much is a kilogram of bananas, and how many mangoes? - Physics - pressure
Find the pressure exerted by a crawler tractor of mass 30 t standing on a flat road if the area of the contact surface of the belts with the ground is 6 m square. - Calculate 33911
Calculate the volume of 50% KI solution and the volume of 20% KI solution needed to prepare 180g of 30% KI solution. The solution densities are known: ρ50% = 1.54575 g / cm3, ρ20% = 1.16597 g / cm³. - Concrete column
The concrete column of the highway bridge has the shape of a block with dimensions of 1m x 0.8m x 25m. Crane should lift it to a height of 20m. What is the power of his engine if the lifting takes 2 minutes? - Packaging 32643
The packaging of Horalka says A wafer with peanut cream filling (72%) in cocoa icing. How many kg fills them together in 1 package, which contains 56 pieces of this wafer, if one weighs 50 g? - Mixture of coffee
They have to prepare a mixture of coffee in packing centers, so 1 kg costs 240 CZK. There are two types of coffee in stock at the price of 220 CZK per 1 kg and 300 CZK per 1 kg. How many kilograms of each species need to be mixed to prepare 50 kg of the r - Chained winch
When digging a well, a chained winch balances the material. An empty shackle weighs 8 kg, a total of 64 kg. What force must the worker exert on the crank handle when pulling the shackle with a constant movement from a depth of 5 m if the shaft diameter is - Block-shaped 29941
Please calculate according to Pascal's law. Kerosene in a block-shaped metal tank reaches a height of 180 cm. Calculate the force acting on the bottom with dimensions of 1.5m and 3m if the density of kerosene is 820kg per M3. - Natural fertilizer
The gardener fertilized the rectangular garden measuring 120m and 60m with 16kg of natural fertilizer. Natural fertilizer contains 45% organic matter. How much organic matter falls on 1 m² of the garden? - The water barrel
The water barrel weighs 122 kg. If we pour 75% of the water out of it, it will weigh 35 kg. What is the weight of the barrel? - Brothers 29471
The two brothers are 41 years old. One is seven years older than the other. How old is your younger brother? - Two teas
The tea shop made a mixture weighing 10 kg from two types of tea. The price of the tea was 160 CZK/kg, and the second tea was 170 CZK/kg. The cost of the mixture is 166 CZK/kg. How many kilograms of each type of tea had to be mixed?
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