SOLVE THE FOLLOWING NUMERICALS:
1. The wavelength of light of a particular colour is 4000 angstrom. Express it in micron.
2. The distance of a Galaxy from the Earth is 8.2 x 10 27 m assuming the speed of light to be 3 x10 m/s.
Find the time taken by light to travel this distance.
3. The mass of a nitrogen atom is 14 u, find its mass in kilogram.
4. The distance of a star from the Earth is 16 light minutes, what do you mean by this statement?
Express the distance in m.
5. Compare the time periods of two pendulums of length 4 m and 16 m.
6. The time period of two simple pendulums at a place are in the ratio 3:2, what will be the ratio of their
lengths?
7. It takes 0.2 seconds for a pendulum bob to move from one end to the other end, what is the time
period of pendulum?
8. A body starts from rest and acquires a velocity 30 m/s in 6 s, find its acceleration.
9. Express 30 m/s in km/h.
10. A toy car initially moving with a uniform velocity of 72 km/h comes to a stop in 10 s, find the
retardation of the car in SI units.
Answers
Answer:
Explanation:
1) 10.37 eV
3)Therefore 14 amu is 14 x 1 gram divided by Avogadro's Number. The atomic, not molar mass of nitrogen is 14U.
4)The statement 'The distance of a star from the earth is 16 light minutes' means that the light from the star takes 16 minutes to reach earth.
5)This means that it takes 8.33 minutes for light from the sun to reach earth. Large distance like these are measured in light year or light minutes. Light year:distance covered by light in 1 year. Light minute: distance covered by light in 1 minute.
6) answer: 9:4
Explanation:
let the length of pendulum be x and y
then ratio of length will be x:y
Now we know that time period is directly proportional to square root of the length
According to this
√x/√y =3:2
Now x/y =3²/2² =9/4
7)1.4 sec wil be the time period of it
8)The acceleration
= rate of change of velocity
= change in velocity/time frame
= ∆v/∆t
= 30/6
= 5m/s^6
9)108km/h
10)other examples:-A toy car initially moving with a uniform velocity of 72 km/h comes to a stop in 10 s, find the
retardation of the car in SI units.