Advertisements
Advertisements
Question
A certain freezing process requires that room temperature be lowered from 40°C at the rate of 5°C every hour. What will be the room temperature 10 hours after the process begins?
Advertisements
Solution
Initial temperature = 40°C
Change in temperature per hour = −5°C
Change in temperature after 10 hours = (−5) × 10 = −50°C
Final temperature = 40ºC + (−50ºC) = −10°C
RELATED QUESTIONS
Find the product, using suitable properties:
26 × (− 48) + (− 48) × (− 36)
Find the product, using suitable properties:
(− 57) × (− 19) + 57
Find the following product: (– 25) × 37 × 4
Find the following products: (– 20) × (– 2) × (– 5) × 7
Find (– 35) × (– 98).
Find 52 × (– 8) + (–52) × 2
The given table shows the freezing points in °F of different gases at sea level. Convert each of these into °C to the nearest integral value using the relation and complete the table,
`C = 5/9 (F - 32)`
| Gas | Freezing Point at Sea Level (°F) |
Freezing Point at Sea Level (°C) |
| Hydrogen | –435 | |
| Krypton | –251 | |
| Oxygen | –369 | |
| Helium | –458 | |
| Argon | –309 |
In a test, +3 marks are given for every correct answer and –1 mark are given for every incorrect answer. Sona attempted all the questions and scored +20 marks though she got 10 correct answers.
- How many incorrect answers has she attempted?
- How many questions were given in the test?
In a true-false test containing 50 questions, a student is to be awarded 2 marks for every correct answer and –2 for every incorrect answer and 0 for not supplying any answer. If Yash secured 94 marks in a test, what are the possibilities of his marking correct or wrong answer?
A multistorey building has 25 floors above the ground level each of height 5 m. It also has 3 floors in the basement each of height 5 m. A lift in building moves at a rate of 1 m/s. If a man starts from 50 m above the ground, how long will it take him to reach at 2nd floor of basement?
