# Unit conversion - 8th grade (13y) - math problems

#### Number of problems found: 331

- Alcohol from potatoes

In the distillery, 10 hl of alcohol can make from 8 t of potatoes. The rectangular field with dimensions of 600 m and 200 m had a yield of 20 t of potatoes per hectare. How many square meters of area are potatoes grown to obtain one liter of alcohol? - Telegraph poles

The bases of two adjacent telegraph poles have a height difference of 10.5 m. How long do the wires connect the two poles if the slope is 39° 30´? - Closed circuit

In a closed circuit, there is a voltage source with U1 = 12 V and with an internal resistance R1 = 0.2 Ω. The external resistance is R2 = 19.8 Ω. Determine the electric current and terminal voltage. - Nitrogen

One bag of urea containing 46 percent nitrogen weighs 25 kg. How many bags have to be purchased for fertilizing a field of 41003 square meters if the nitrogen dose is 50.0 kg per hectare? - Beer tapping

When checking compliance with the beer tapping, it was found that 60% of the offered beers were underfilled. The others were fine. Thus, instead of 0.5 l, the volume was 4.4 dcl on average. What was the volume of one average underfilled beer? - Concrete hatch

The concrete hatch for a round well has a diameter of 1300 mm and a thickness of 80 mm. Determine its weight in kg if the density of the concrete is 2545 kg/m3 - Calculate

Calculate the surface of a regular quadrilateral prism whose base edge is 2.4dm and the height of the prism is 38cm. - The water tank

The water tank has the shape of a sphere with a radius of 2 m. How many liters of water will fit in the tank? How many kilograms of paint do we need to paint the tank, if we paint with 1 kg of paint 10 m^{2}? - Copper Cu wire

Copper wire with a diameter of 1 mm and a weight of 350 g is wound on a spool. Calculate its length if the copper density is p = 8.9 g/cm cubic. - AMSL and skiing

Tomas skis from point A (3200m above sea level to place B. Hill has 20% descent. The horizontal distance between the start and finish is 2,5km. At what altitude is point B? - Eight masons

Eight masons will plaster a wall with an area of 1440 m^{2}in 9 days. They work 8 hours a day. How much area will plaster 6 masons in 4 hours? - Average speed

The average speed of a pedestrian who walked 10 km was 5km/h, the average speed of a cyclist on the same track was 20km/h. In how many minutes did the route take more than a cyclist? Q - Inclined plane

The body stays on an inclined plane and exerts a compressive force of 70N on it. Find the angle between the inclined plane and the horizontal if a gravitational force of 100N acts on the body. - Cooker

A current of 2A passes through the immersion cooker at a voltage of 230V. What work do the electric field forces in 2 minutes? - Cylinder

The 1.8m cylinder contains 2000 liters of water. What area (in dm^{2}) of this container is the water? - Cheops pyramid

The Pyramid of Cheops is a pyramid with a square base with a side of 233 m and a height of 146.6 m. It made from limestone with a density of 2.7 g/cm3. Calculate the amount of stone in tons. How many trains with 30 twenty tons wagons carry the stone? - Ping time

Calculate theoretical ping time between Orlando and Shenzhen which is 14102 km distant. Ping time measures the round-trip time for small messages sent from the origin to a destination that is echoed back to the source. The name comes from active sonar ter - Garden exchange

The garden has the shape of a rectangular trapezoid, the bases of which have dimensions of 60 m and 30 m and a vertical arm of 40 m. The owner exchanged this garden for a parallelogram, the area of which is 7/9 of the area of a trapezoidal garden. What is - Largest wall

Find the content of the largest wall of a prism with the base of a rectangle which has a height of 4 dm, side c = 5 cm, and side b = 6 cm. - The conical

The conical candle has a base diameter of 20 cm and a side of 30 cm. How much dm ^ 3 of wax was needed to make it?

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