Mass + reason - examples
- Friction coefficient
What is the weight of a car when it moves on a horizontal road at a speed of v = 50 km/h at engine power P = 7 kW? The friction coefficient is 0.07
- Centroid - two bodies
A body is composed of a 0.8 m long bar and a sphere with a radius of 0.1m attached so that its center lies on the longitudinal axis of the bar. Both bodies are of the same uniform material. The sphere is twice as heavy as the bar. Find the center of gravit
- Luggage and air travel
Two friends traveling by plane had a total of 35 kg of luggage. They paid one 72 CZK and second 108 CZK for being overweight. If only one paid for all the bags, it would cost 300 CZK. What weight of baggage did each of them have, how many kilograms of lugg
- Brick weight
The brick weighs 2 kg and a half bricks. How much does one brick weigh?
In human body the blood is about 7.2% body weight. How many kilograms of blood is in the human body with weight 93 kg?
- Eiffel Tower
Eiffel Tower in Paris is 300 meters high, is made of steel. Its weight is 8000 tons. How tall is the tower model made of the same material, if it weigh is 2.4 kg?
- Cu thief
The thief stole 122 meters copper wire with cross-section area of 95 mm2. Calculate how much money gets in the scrap redemption, if redeemed copper for 5.5 eur/kg? The density of copper is 8.96 t/m3.
What power has a pump output to move 4853 hl of water to a height of 31 m for 8 hours?
Imagine a word solidarity means that salt donation to the needy, who have neither the salt. If we take word solidarity has word base salt + gift (only in Slovakian language). Calculate how many kilos of salt sympathetic citizen "gives" government a year i
- Tea blend
Tea blends are maked from two kinds of tea. In standard tea mixture are two teas in the ratio 1:3 and 40 g costs 42 CZK. In the premium tea mixture are weighing two teas in the ratio 1:1 and 50 grams costs 60 CZK. How much cost 10 grams of more expensive k
- Sea on the Moon
Assume that the Moon has sea, the same composition as on the Earth (has same density of salt water). Calculate dive of boat floating in the sea on the Moon, when on Earth has dive 3.6 m. Consider that the Moon has 6.5-times smaller gravitational accelerati
Calculate how many 25 kg bags of leveling concrete must be purchased if we leveling room 15 m2 to the "height" 6 mm if consumtion is 1.5 kg per square meter and millimeter thickness.
Mother bought 5 boxes of milk and 7 kg of potatoes and paid a total CZK 147. Aunt bought 7 boxes of milk and 3 kg of potatoes and paid 131 CZK. What is the price of one carton of milk and 1 kg of potatoes? How CZK together would have saved if bought at the
Grower harvested 190 kg of apples. Pears harvested 10 times less. a) How many kg pears harvested? b) How many apples and pears harvested? c) How many kg harvested pears less than apples?
The baker makes from 10 kg of flour 12 kg dough. How much flour he need to make a 100 kg dough?
- The horses
A couple of horses consume 88 kg of oats for 14 days. How many oats consumed 7 horses at the same consumption for 6 days?
20 cows has food for 60 days. We reduce the dose to two-thirds for 18 cows. How many days will be fed?
- Bob and Bobek
Bobek has 2 cabbages and 5 carrots, Bob has 2 cabbages and 9 carrots. When Bobek stepped on the scale weight 5800 g and when Bob weight 8960 g. Actual Bob weight is 8 kg and Bobek 5 kg. How much weighs one carrot?
- Nine balls
Imagine that you have exactly the same appearance nine balls of which one has a greater mass than the other. You have isosceles weights. Post a procedure as you would using a weights to discover heavier balls. How many measurements at least you have to do?
- Sumo competition
In the competition for the heaviest man was 5 competitors. The first three together weighed 553 kg. What is the minimal weigt of winner, if a contestant weighed with an accuracy of one kilogram.