Answer:
They can't hear an echo in small room because in it the sound can't be reflected back. For an echo of a sound to be heard,the minimum distance between the source of sound and the walls of the room should be 17.2 m.
hopw it helps
Answer:
A. Gamma decay
Explanation:
A form of nuclear decay in which the atomic number is unchanged is a gamma decay.
The atom has undergone a gamma decay.
In a gamma decay, no changes occur to the mass and atomic number of the substance.
- Gamma rays have zero atomic and mass numbers.
- When they cause decay, they cause no change to the mass and atomic numbers.
- They simply produce gamma rays during such reactions and these rays are very energetic.
Answer:
Explanation:
Given
Temperature of Room
Area of Person
Temperature of skin
Heat transfer coefficient
Emissivity of the skin and clothes
Total rate of heat transfer=heat Transfer due to Radiation +heat transfer through convection
Heat transfer due radiation
where
Heat Transfer due to convection is given by
The kinetic energy is the same as the potential energy of raising it 40cm (0.4m). That's mgh where m is mass of ball. Its then 3.924*m, whatever m is equal to in kg.