**Guess questions term-2 Science IX SUBJECT- PHYSICS**

Q1: What is the relation between speed of sound, frequency and wavelength?

Q2: Which travels faster sound of light, also discuss the speed of fastest one In solids, liquids and solids?

Q3: A source of wave produces 20 crests and 20 troughs in 0.2s. Find the Frequency of the wave?

Q4: Will a vibrating source always produce sound?

Q5: What are supersonics, infrasonic and ultrasonic waves?

Q6: Can sound waves travel through vacuum?

Q7: Does the sound of a bomb explosion travel faster than the sound produced By a humming bee?

Q8: If an observer places his ear at the end of a long pipe, he can hear two Distinct echoes when the pipe is hammered at the other end. Explain.

Q9: A ship sends out ultrasound that results from the seabed and is detected After 3.42s. If the speed of ultrasound through sea water is 1531m/s. , what is the distance of the sea bed from the ship?

Q10:What is density? Give its units.

Q11: A force of 15N is uniformly distributed over an area of 150m2. Find pressure In Pascal?

Q12: Differentiate between mass and weight?

Q13: What is the relation between thrust and pressure?

Q14: What is the relation between acceleration due to gravity and Gravitational Constant?

Q15: What happens to a body when the density of a body is equal to the density of the liquid?

Q16: A body of mass 2kg floats in a liquid, what is the buoyant force on the body?

17Q: A coolie carries a load of 50kg on his head and walks on a level road up to 100m.What is the work done by him?

18 Q: Give units of Power, Work and Energy?

19 Q: What is the commercial unit of energy?

20Q:Two bodies have their masses m1/m2 =3 and their kinetic energy E1/E2=1/3 .The ratio of their velocities are?

21Q:Prove that P=F * v , where P is power, F is force and v is velocity?

22Q:An electric motor creates a tension of 4500N in hoisting a cable and reels at a rate of 2m/s. The Power of the motor is?

23 Q: State Work Energy theorem?