Answer:hot air
Explanation:Hot air goes up, so when you put it in a hot air balloon fire is placed at the oppening to creat hot air and lift the balloon! :)
Answer: A. They will be repelled because they are in each other's magnetic
field.
Explanation: Apex and gravity and electrical don't have effect on magnets magnetic field.
C. unbalanced is the correct answer for newton's first law.
Answer:
a) 3-in. pipe
Explanation:
Given that
Fluid flow is in same amount in the same time it means that volume flow rate is same for the pipes
Volume flow rate
Q = A V
A=Area ,V=Velocity

If diameter d is more then the velocity will be less for same volume flow rate .We also Know that if pressure is more then the velocity will be less.
The second pipe 3 in diameter having more diameter then the velocity will be less but the pressure will be more.
That is why the 3 in diameter is having more pressure than 2 in diameter pipe.
Therefore the answer will be a.
a) 3-in diameter pipe
Answer:
beats per second
Explanation:
Number of heart beats = 
time taken = 
now we have
%
%
now rate of heart beat is defined as number of heart beat per unit of time
so we have


so we have

%
beats per second