Answer:
f = 8 %
Explanation:
given,
density of body of fish = 1080 kg/m³
density of air = 1.2 Kg/m³
density of water = 1000 kg/m²
to protect the fish from sinking volume should increased by the factor f
density of fish + density of water x increase factor = volume changes in water
1080 +f x 1.2 =(1 + f ) x 1000
1080 + f x 1.2 = 1000 + 1000 f
998.8 f = 80
f = 0.0800
f = 8 %
the volume increase factor of fish will be equal to f = 8 %
To calculate the mass of the fuel, we use the formula
Here, m is the mass of fuel, V is the volume of the fuel and its value is 
and 
is the density and its value of 0.821 g/mL.
Substituting these values in above relation, we get
Thus, the mass of the fuel 247 .94 kg.
The minimum initial speed of the dart so that the combination makes a complete circular loop after the collision is 58.5 m/s.
<h3>Minimum speed for the object not fall out of the circle</h3>
The minimum speed if given by tension in the wire;
T + mg = ma
T + mg = m(v²)/R
tension must be zero for the object not fall
0 + mg = mv²/R
v = √(Rg)
<h3>Final speed of the two mass after collision</h3>
Use the principle of conservation of energy
K.Ef = K.Ei + P.E
¹/₂mvf² = ¹/₂mv² + mg(2R)
¹/₂vf² = ¹/₂v² + g(2R)
¹/₂vf² = ¹/₂(Rg) + g(2R)
vf² = Rg + 4Rg
vf² = 5Rg
vf = √(5Rg)
vf = √(5 x 2.8 x 9.8)
vf = 11.7 m/s
<h3>Initial speed of the dart</h3>
Apply principle of conservation of linear momentum for inelastic collision;
5v = vf(20 + 5)
5v = 11.7(25)
5v = 292.5
v = 58.5 m/s
Learn more about linear momentum here: brainly.com/question/7538238
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Answer:
1. In a coal-fired power plant, chemical energy is first converted to thermal energy. TRUE.
The chemical energy in the coal is converted to thermal energy when the coal is burnt to produce steam.
2. In a coal-fired power plant, approximately 2/5 of original energy in the coal is lost to heat. FALSE.
Approximately 3/5 of the original energy is lost not 2/5 so this statement is false.
3. The molecules in cold air move faster than in hot air. FALSE.
Molecules with more heat move faster than molecules with less. Molecules in cold air therefore, will move slower than molecules in hot air.
