Science and Technology for BLE

Important Numerical Questions:
1. The distance travel by a bike is 1.8 km in 36 seconds. Find its speed.
2. The velocity of an object is 240 m/s in 4.8 seconds. Find the displacement covered by an object.
3. The velocity of the car starts moving from the rest is 60 m/s in 12 seconds. Calculate the acceleration of the car.
4. A bus with a velocity of 40 m/s stops after 8 seconds by applying brake on it. Calculate the acceleration of the bus.
5. A moving bus with velocity 40 m/s stops after 8 seconds by applying brake on it. Calculate the acceleration of the bus.
6. A mass of an object is 250 Kg and acceleration due to gravity is 9.8 m/s2. Calculate the weight.
7. Find the average velocity for a particle which travels 9 m distance in 2 seconds and 6 m distance in another 3 seconds.
8. Convert: 180 km/h into m/s.
9. Two cars are moving with velocities of 80 Km/h and 60 Km/h. Find the relative velocities of the first car with respect to the second car.
a. When both cars travel in the same direction.
b. When both cars travel in the opposite direction.
10. A lever is used to lift 1600 N load. If the total length of the lever is 6 m including 2.5 m load distance, then calculate:
a. Effort
b. Velocity Ratio
c. Mechanical Advantage
d. Efficiency
11. The distance travel by a man is 20 m in 50 seconds. Calculate his speed.
12. The applied force on an object is 1800 N in a surface area of 7 square meter. Calculate the pressure exerted by an object.
13. A container whose height is 2 meters filled with liquid having the density 1200 kg/cubic meter. Find the pressure exerted by liquid. (Use: g = 9.8 meter per square second)
14. The height of the dam is 12 m where the two-third part of the dam is filled by water. Calculate the pressure exerted by the water in a dam.
15. The speed of sound is 4800 m/s and wave length is 8 m. Find the frequency of Sound.
16. The wave length of sound is 3.5 Hz and frequency is 108.55 Hz. Calculate the velocity of sound.
17. The frequency of sound is 2.5 KHz and wave length is 4. 5 m. Calculate the velocity of sound.
18. The speed of sound is 3600 m/s and frequency is 25 Hz. Find the frequency of Sound.
19. If 5 fans each power 100 W used for 6 hours per day. Calculate the electricity consumption in a day.
20. If a machine has power 2500 W used for 8 hours 30 minutes per day. Calculate the electricity consumption by a machine in a month.
21. The electric meter of the house records 25 units of consumption of electricity in a day. Calculate the average monthly electricity bill of a house if the cost of electricity is Rs. 8.5 per unit.
22. In a certain place, the municipality installed 14 street lights each rated 1500 W. These street lights are used for 6.5 hours daily on average. If the municipality has to pay the electricity bill at the rate of Rs 12.50, calculate the monthly bill paid by the municipality to the electricity authority for using these street lights.
23. If 12 bulbs each power 60 W is used to light for 2 hours 15 minutes in a day.
a. Calculate the energy consumed by the bulbs in a day.
b. If the cost of electricity is Rs. 12 per unit then, find the electricity bill of the house in a month.

Short Questions
1. What does Big Bang theory explain?
The Big Bang Theory explains the origin of the universe, suggesting it began about 13.8 billion years ago from a tiny, hot, and dense point that expanded rapidly.
2. What is the scheme of the solar system?
The solar system consists of the Sun, eight planets, their moons, dwarf planets, asteroids, comets, and other celestial bodies orbiting the Sun.
3. What is meant by "Milky Way"?
The Milky Way is the galaxy that contains our solar system, appearing as a band of light in the night sky due to its countless stars.
4. How are constellation formed?
Constellations are patterns of stars in the sky, formed by grouping stars based on their positions as seen from Earth.

5. Give Reasons
a. The distance of stars is measured in light years.
Stars are extremely far from Earth, so their distance is measured in light years, the distance light travels in one year, for convenience.
b. Large meteorites occasionally fall on the Earth.
Meteorites fall when large rocks from space enter the Earth's atmosphere and survive the journey to the surface.
c. Big Bang is the most accepted theory on the origin of the universe.
The Big Bang is widely accepted because it explains the expansion of the universe, cosmic background radiation, and the abundance of elements like hydrogen and helium.

6. Differentiate Between
a. Geocentric Theory and Heliocentric Theory
Geocentric Theory: Earth is at the center of the universe (proposed by Ptolemy).
Heliocentric Theory: The Sun is at the center, and planets orbit around it (proposed by Copernicus).
b. Stars and Planets
Stars: Massive, luminous celestial bodies that emit light and heat.
Planets: Celestial bodies that orbit stars and do not emit their own light.
c. Meteorites and Meteoroids
Meteorites: Space rocks that reach the Earth's surface.
Meteoroids: Small rocks or debris floating in space.

Long Questions
1. What is universe? Explain the constituents of the universe.
The universe is the vast space that contains everything, including all matter, energy, galaxies, stars, planets, and other celestial objects.
Constituents of the Universe:
Galaxies: Massive systems of stars, gas, and dust (e.g., Milky Way).
Stars: Luminous celestial bodies made of gases like hydrogen and helium.
Planets: Celestial bodies orbiting stars (e.g., Earth).
Nebulae: Clouds of gas and dust where stars are born.
Black Holes: Regions with gravitational force so strong that nothing can escape.