Answers:
a) 5400000 J
b) 45.92 m
Explanation:
a) The kinetic energy
of an object is given by:

Where:
is the mass of the train
is the speed of the train
Solving the equation:

This is the train's kinetic energy at its top speed
b) Now, according to the Conservation of Energy Law, the total initial energy is equal to the total final energy:


Where:
is the train's initial kinetic energy
is the train's initial potential energy
is the train's final kinetic energy
is the train's final potential energy, where
is the acceleration due gravity and
is the height.
Rewriting the equation with the given values:

Finding
:
Answer:
Planets that are farther from the sun than the earth (all but Mercury and Venus) will exhibit retrograde motion.
If the position of the planet is observed relative to the background stars, the planet will appear to move backward relative to the stars when the earth is moving in an Eastward direction faster than the planet, and the planet appears to move backwards relative to the stars
(The planet will be on the side of the earth that is opposite that of the sun)
Answer:
Drag or air resistance
Explanation:
The force of friction caused by a moving fluid is called drag. When that fluid is air, it's also known as air resistance.
Answer:
The volume of the block is equal to the volume of water displaced by the block.
Explanation:
Volume refers to the amount of space occupied by a given object (in this case the block). When an object such as the block is immersed in water, it displaces its own volume of water. This volume of water displaced is equal to the volume of the block. Hence we can write;
Final Volume of water - Initial Volume of water= Water Displaced = Volume of the block
Recall that the density of a body is given by;
Density= mass/volume
If we obtain the volume of the block by measuring the volume of water displaced by the block, then we weigh the block using a weighing balance, we can obtain the density of the block easily from the relationship shown above.