Percentages + power - practice problems - page 2 of 3
Number of problems found: 52
- Power input
The construction lift lifted a load weighing 300 kg to a height of 12 m with a uniform movement. How long has it taken for the load to be lifted if the efficiency is 75% and the engine has a power input of 5 kW? - Temperature 7595
Colorless liquid weighing m = 200 g is heated with constant stirring on a stove with power input P0 = 600W. 80% of the supplied energy is used to heat the liquid. Selected measured values of liquid temperature as a function of time are recorded in the t - Statistician 7500
A statistician monitored the variance of monthly wages and found its value to be 640,000. Determine the standard deviation of salaries if there is a one-off increase: a) about CZK 1,800, b) about 5%. - Helmet
Nowadays, better results can be obtained in cycling due to the rider's physical preparation and updated technologies. One of the essential parts of the rider's equipment is their helmet. While most bikers wear a helmet mainly to protect themselves, racers
- Orlík hydroelectric plant
The Orlík hydroelectric power plant, built in 1954-1961, consists of four Kaplan turbines. For each of them, the water with a flow rate of Q = 150 m3/s is supplied with a flow rate of h = 70.5 m at full power. a) What is the total installed pow - Precious metals
From 2006-2009, the value of precious metals changed rapidly. The data in the following table represent the total rate of return (in percentage) for platinum, gold, and silver from 2006 through 2009: Year Platinum Gold Silver 2009 62.7 25.0 56.8 2008 -41. - Pyramid cut
We cut the regular square pyramid with a parallel plane to the two parts (see figure). The volume of the smaller pyramid is 20% of the volume of the original one. The bottom of the base of the smaller pyramid has an area of 10 cm². Find the area of the or - Performance
Two masons with the same performance would have been made of plaster for six days. One of them, however, has increased its daily performance by 50%. How long would it take them now to make plaster together? - Measuring 6357
Determine the length of the edge of the cube, the surface of which is equal to 60% of the surface of a block measuring 7cm, 8cm, 6cm
- Line-producing 6197
The new line-producing screws did not work at total capacity from the beginning. On Monday, she produced 20% of the daily norm. On Tuesday, she already met 4/5 of the daily norm. By what percentage was the number of screws made on Tuesday higher than on M - Calculate 6195
The number x = 2 / p² is given. Calculate a number 400% greater than x if p = 10. - Measuring 6188
Find the length of the cube's edge and its volume is equal to 60% of the volume of a block measuring 7 cm, 8 cm, and 6 cm. - Cube edges
If the edge length of the cube increases by 50%, how does the volume of this cube increase? - Volume and body diagonal
Calculate how much the cuboid's volume and body diagonal decrease if we reduce each of its three edges, a, b, and c, by 18%.
- Decreases 5625
How much percent will the surface and volume of the cube decrease if the diagonal decreases by 10%? b) if the diagonal increases by 10%? - Unknown variable
Find the number x, which if it increases by 2, then its square increases by 21 percent. - Rate or interest
At what rate percent will Rs.2000 amount to Rs.2315.25 in 3 years at compound interest? - Job task
After two hours and 40 minutes, the job is finished. Compared to last year, we were 40 minutes faster. What is the percentage increase in our performance? - Efficiency 4073
Determine the efficiency of a vacuum cleaner with a power input of 1.2 kW when the suction power is 360 W.
Do you have homework that you need help solving? Ask a question, and we will try to solve it.