For physics, I would recommend to just keep doing practice problems and reviewing notes. Repetition of the same concepts will help drill it into your brain. Hope that helps!
The answer is A. voice uses a wider range of pitch and volume as compared to speaking
Force on a moving charge is given by formula

here we know that this force will be maximum when velocity is perpendicular to magnetic field

here we know that



now we have


<span>No. Work is not done if you carry a book across the room
at a constant velocity?
The force applied is perpendicular to the direction of motion. (C)</span>
Answer:
The the specific volume and weight are 79.16m³/k mol and 49 N.
Explanation:
Given that,
Diameter = 3 m
Mass of N₂ = 5 kg
We need to calculate the volume of balloon
Using formula of volume




We need to calculate the specific volume in the balloon



Now, Molar mass of N₂ gas is 0.028 kg/mol
Now, Specific volume of N₂ gas in the balloon is


(b). We need to calculate the weight of the gas in the balloon
Weight of the balloon is dependent on the mass of the gas.
The weight of the gas is given by



Hence, The the specific volume and weight are 79.16m³/k mol and 49 N.