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.
Answer:

Explanation:
Given that,
The mass of a Hubble Space Telescope, 
It orbits the Earth at an altitude of 
We need to find the potential energy the telescope at this location. The formula for potential energy is given by :

Where
is the mass of Earth
Put all the values,

So, the potential energy of the telescope is
.
Answer:
Kinetic energy, E = 133.38 Joules
Explanation:
It is given that,
Mass of the model airplane, m = 3 kg
Velocity component, v₁ = 5 m/s (due east)
Velocity component, v₂ = 8 m/s (due north)
Let v is the resultant of velocity. It is given by :


Let E is the kinetic energy of the plane. It is given by :


E = 133.38 Joules
So, the kinetic energy of the plane is 133.38 Joules. Hence, this is the required solution.
The speed of an object can be determined from the distance vs time graph.
You know that speed = distance/time
in the graph, distance/time = slope of the curve.
So SPEED IS GIVEN BY THE SLOPE of the curve in the graph.
● If the distance vs time curve is a straight line, parallel to time axis(x-axis), slope is 0. That means speed is 0. So the object is at rest.
● If the distance vs time curve is a straight line, with some non-zero slope; That means speed is nonzero and constant. So the object is in uniform motion.
● If the distance vs time curve is a curved, the slope is changing. That means speed is changing. So the object is in an accelerated motion.
Explanation:
"Static friction is a force that keeps an object at rest. It must be overcome to start moving the object."
(556 x 0.68) = static friction of 378.08N. before movement occurs.
The forces (a) and (b) will not move it.
Each will incur a frictional force preventing movement equal to itself, = 222N. and 334N. respectively.
Forces (c) and (d) will move it, and accelerate it.
Forces (c) and (d) will both encounter friction of (556 x 0.56) = 311.36N. when the cabinet is moving.