The specific gravity of the object’s material is 5.09.
<h3>To calculate the specific gravity of the object:</h3>
Weight difference = 9 - 7.2 = 1.8 N = Buoyant force of water
Buoyant Force in water(Fb) = density of water x g x volume of the body(Vb)
1.8 = 1000 x 9.81 x Vb
Vb = 1.8/9810 cubic meter
Now, in the air;
Weight of body = mg = 9 N
Mass of body,m = 9/9.81 Kg
So,
Density of body = m/ Vb
= 9/9.81 ÷ 1.8/9810
= 5094.44 kg per cubic meter
The specific gravity of body = density of body ÷ density of water
= 5094.44 ÷ 1000
= 5.09
Therefore, Specific gravity of body = 5.09
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Answer: 52%
Explanation:
1W = 1 J/s
motor input is 10000 J/s
Potential energy change
PE = 955(9.81)(25.0) = 234,213.75
power needed to change the PE in that time
P = 234,213.75/ 45 = 5,204.75 Watts
motor is 5204.75 / 10000 = 0.520475 or 52% efficient
Potential energy is when the roller coaster rises. Kinetic energy is when the roller coaster declines.
