Answer:
Millions of years.
Explanation:
Fossil fuels are fuels formed by natural processes. It involves decomposition of dead and decaying animals, marine and plants for over million years. This some times take more than hundred million years to convert into fuel. This is why they are called non renewable resources of energy. The decomposition of dead plant species forms coal and decomposition animals of land and sea forms crude oil and gas.
A heat engine would be less efficient due to many factors
For instance, a heat engine is more efficient when it uses in cold weather because there is a greater temperature difference ( Carnot Efficient )
A heat engine could be less efficient because of friction
Hope it helps I am a beginner
Answer:
(C) greater than zero but less than 45° above the horizontal
Explanation:
The range of a projectile is given by R = v²sin2θ/g.
For maximum range, sin2θ = 1 ⇒ 2θ = sin⁻¹(1) = 90°
2θ = 90°
θ = 90°/2 = 45°
So the maximum horizontal distance R is in the range 0 < θ < 45°, if θ is the angle above the horizontal.