Cars are the mechanical device which convert chemical energy of fuel into mechanical energy, the engine used in the automobiles car are very inefficient, they can only convert 30-40% of chemical energy of fuel into mechanical energy, since thermodynamics is the branch of science that deals with the conversion of energy, thus due to poor conversion rate of chemical energy into mechanical energy, cars are known as inefficient machine.
Answer:
The fraction of the object that is below the surface of the water is ¹⁷/₂₀
Explanation:
Given;
specific gravity of the object, γ = 0.850
Specific gravity is given as;

Fraction of the object's weight below the surface of water is calculated as;

Therefore, the fraction of the object that is below the surface of the water is ¹⁷/₂₀
Answer:
0.037 A
Explanation:
Magnetic field = B = 1.00 e-4 T
Length = L = 0.380 m
Number of turns = 810
B = μ₀ N I / L
⇒ Current = I = B L / μ₀ N = ( 1 e-4) ( 0.380) / (4π × 10⁻⁷)(810)
= 0.037 A = 37.3 mA
Answer : 6.022• 10^23 atoms of potassium