![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
There is a kind of metal with a mass of 81g and a volume of 30 cubic centimeters. Find the density of the metal and judge which metal it is?
81 / 30 = 2.7g/cm3
aluminium
The mass of a metal is 316g and its volume is 40CC. If you cut it off by 1 / 3, what is the mass and density of the remaining part?
The mass of a certain metal is 316g and its volume is 40 cubic centimeter. If one third of it is cut off, what is the mass and density of the remaining part?
Solution M = 316 * 2 / 3 ≈ 211 (g)
Density does not change with mass,
The density is: M / v = 7.9g/m3
A: the mass of the remaining part is 211g and the density is 7.9g/m3
A hollow iron ball with a mass of 158 g and a volume of 25 cubic cm is known. The density of iron is 7.9 * 10 cubic kg / m3
(1) Is the ball solid or hollow?
(2) How to calculate the volume of the hollow part?
(1)25*7.9=197.5>158
So it's hollow
(2)158/7.9=20
25-20=5cm^3
RELATED INFORMATIONS
- 1. There is an iron ball with a mass of 32 grams and a volume of 8 cubic centimeters. Is it solid? (the density of iron is 7.8 grams per cubic centimeter.)
- 2. Xiao Jie found a metal block, and he wanted to know its gravity and density. He only had a spring scale with small range in his hand. When he used the spring scale to measure the gravity of the metal block, he found that it had exceeded the maximum range of the spring scale, so he designed the device as shown in the figure to measure. In the figure, OA: OB = 1:3, the metal block was suspended at point a with a string, and the spring scale was used at point B When a vertical upward force is applied, when the OB lever is horizontally stationary, the reading of the spring scale is 1.8n. When water is added to the container and the metal block is immersed in water, the reading of the spring scale is 1.2N, G is 10N / kg? (2) What is the buoyancy of a metal block when it is immersed in water? (3) What is the density of the metal block?
- 3. The gravity of a stone is 5N in the air and 2n in the water
- 4. How many cubic meters is one cubic meter? And the relevant formula
- 5. ______ Liter is 13 less than 12 liter, 8 cubic meter is more than 5 cubic meter______ %．
- 6. How many cubic meters is 10 meters
- 7. 35% of 2.4 tons is () tons; 120 cubic meters is more than 100 cubic meters (); 20 square meters is less than 25 square meters ()
- 8. The area of a room is 20 square meters, paved with 1 meter long, 1 decimeter wide, 2 cm thick wood floor, at least () cubic meters of wood floor
- 9. How to measure the density of rice grain with density bottle
- 10. Density of rice
- 11. There is a piece of metal with a mass of 386 kg and a volume of 20 cubic centimeters. The density of this metal is () kg / m3
- 12. 3.1 g / cc = how many kg / m3? Such as the title
- 13. Let f (x) satisfy f (x + x ^ - 1) = x ^ 3 + x ^ - 3, then the expression of F (x) is
- 14. It is known that the expression of a function is the square of y = x, and its range is [1,9]. How many such functions are there? Try to write out two of them Set M = {a, B, C}, n = {- 1,0,1}, the mapping f from m to n satisfies the relation f (a) > F (b) > = f (c), then what is the number of mappings? A.1 B.2 C.3 D.4 Given that f (x + 1 under radical) = x + 2 under radical, find f (x)
- 15. Let f (x) = 1-1 / x + x square judge its parity and prove f (1 / x) = - f (x))
- 16. Let f (x) = one-half of the square of X × the X-Power of E (1) to find the monotone interval of F (x) (2) When x ∈ [– 2,2], the inequality f (x) < m is used to find the value range of real number M
- 17. What function is f (x) = the square of X in X + 1 Why is the domain of definition (0, ∞) ∪ (- ∞, 0) still related to the origin symmetry? If (0, ∞) ∪ (- ∞, 0) is r, then why change that 0 to 1 and it is not related to the origin symmetry? And how to understand the domain of definition [1. - 1]
- 18. The image of the function y = 2x + 3x + 1 is symmetric with respect to the line x = 3. The corresponding analytic expression of the function is?
- 19. When x______ The value of formula 3x-5 is greater than that of formula 5x + 3
- 20. In order to solve the problem of combining similar terms in mathematics, we should make the cube of polynomial MX + 3nxy square - 2x Cube - XY square + y not contain cubic terms, and find the value of M + 3N