Examples for 8th grade - page 14
- Cylinder - A&V
The cylinder has a volume 253. The base has a radius 5. What is the area of surface of the cylinder?
On double track line between stations K and M went against each other two trains. The first train passed the distance between stations for 2 hours, the second, which had an average speed of 15 km/h more passed for 1.55 hours. Calculate the distance betwee
Calculate the circumference and area of the rhomboid with sides 11 and 17, with their angle 70°.
Column with posters in the form of a cylinder is 3.3 m high and its diameter is 1.5 m. What is the content area for which it is possible to stick posters?
The base of the prism is a rhombus with a side 6 cm and height 4 cm. The height of the prism is 188% longer than the side length of the rhombus. Calculate the volume of the prism.
Vojta left the house at three o'clockat 4 km/h. After half hour later went from the same place Filip by bicycle at speed 25 km/h. How long take Tilip to catch up Vojta and how far from the house?
- 4s pyramid
Regular tetrahedral pyramid has a base edge a=6 and collaterally edge length b=15. What is its height?
- Painter Pavel
Painter Pavel painted the fence for 20 hours and painter Petr the same fence painted for 17 h. How long should take painted the fence together?
- Parquet floor
Three workers laid parquet floor for 1.957 hour. The first one would do this work alone 5 hours, the second in 9 hours. For how many hours would fulfill this work the third worker, if he worked alone?
What is the side length of the regular 5-gon inscribed in a circle of radius 11 cm?
- Rhombus 2
Calculate the area of rhombus which has a height v=48 mm and shorter diagonal u = 60 mm long.
- Sugar - cuboid
Pejko received from his master cuboid composed of identical sugar cubes with count between 1000 and 2000. The Pejko eat sugar cubes in layers. The first day eat one layer from the front, second day one layer from right, the third day one layer above. Yet i
- Free fall
Stephen fall from height 5 m. Calculate the speed he hit the ground when falling with acceleration g = 9.81 m/s2
In the trapezoid KLMN is given this informations: 1. segments KL and MN are parallel 2. segments KL and KM has same length 3. segments KN, NM and ML has same length. Determine the size of the angle KMN.
A passenger train traveled for 4 hours 136 km. 2.7 hours after its departure started fast train and caught it on 324 km. How many km/h is different its average speeds?
- Lead cube
Calculate the edge of the cube made from lead, which weighs 11 kg. The density of lead is 11341 kg/m3.
Calculate the length of the arm r of isosceles triangle ABC, with base |AB| = 16 cm and a height v=10 cm.
- Wire D
Wire length 5 m is bent so that it forms a semicircle circuit (including the diameter). Determine the radius of the semicircle.
- Wood in the forest
The amount of wood in the forest was estimated at 24000 m3. How much wood will be in forest after 3 years if the annual growth of wood is 3% each year and logging 360 m3 each year?
Is right that in any right triangle height is less or equal half of the hypotenuse?