Answer:

Explanation:
As we know that the formula of range is given as

now we know that
maximum value of the range of the projectile is given as

now we need to find such angles for which the range is half the maximum value
so we will have




Answer:An incandescent light bulb gives only energy of the system in the form of heat. ... The roof of a house is stable but it receives energy from the surroundings and transfers energy through it towards lower temperature side which includes no mass transfer. So, it is best considered as closed system.
Explanation: