9514 1404 393
Answer:
1.114 kg/m³
Explanation:
The total mass of the air in the balloon and the balloon + cargo will be the mass of the displaced air. If d is the density of the air in the balloon, then we have ...
2910d +308 = 2910×1.22
Solving for d, we find ...
2910d = 2919(1.22) -308
d = 1.22 -308/2910
d ≈ 1.114 . . . kg/m³
The density of the hot air is about 1.114 kg/m³.
Answer:
The angle of projection is 12.26⁰.
Explanation:
Given;
initial position of the dart, h₀ = 1.50 m
height above the ground reached by the dart, h₁ = 1.73 m
maximum height reached by the dart, Hm = h₁ - h₀ = 1.73 m - 1.50 m= 0.23 m
velocity of the dart, u = 10 m/s
The maximum height reached by the projectile is calculated as;
where;
θ is angle of projection
g is acceleration due to gravity = 9.8 m/s²
Therefore, the angle of projection is 12.26⁰.
Answer:
Final angular velocity is 35rpm
Explanation:
Angular velocity is given by the equation:
I1w1i + I2w2i = I1w1f -I2w2f
But the two disks are identical, so Ii =I2
wf can be calculated using
wf = w1i - w2i/2
Given: w1i =50rpm w2i= 30rpm
wf= (50 + 20) / 2
wf= 70/2 = 35rpm
Before you start working on any motion problem, YOU decide which direction you're going to call 'positive'. Everybody almost always calls UP positive, and the acceleration of gravity points down, so it winds up negative. But you could just as well call DOWN the positive direction. Then, the cannonball is fired with a negative vertical speed, and the acceleration of gravity eventually robs all of its negative speed, and makes it start falling in the positive direction. The whole thing is your choice.