Download HighFour General Sciences Round 10 Category A: Grades 4 – 5

HighFour General Sciences
Category A: Grades 4 – 5
Round 10
Monday, June 6, 2016
The use of calculator is not allowed.
Answer #1:
Explanation:
A
In physics, the kinetic energy of an object is the energy that it possesses
due to its motion. It is defined as the work needed to accelerate a body of a
given mass from rest to its stated velocity. Having gained this energy during
its acceleration, the body maintains this kinetic energy unless its speed
changes.
Answer #2:
Explanation:
B
Potential energy is energy which results from position or configuration. An
object may have the capacity for doing work as a result of its position in a
gravitational field (gravitational potential energy), an electric field (electric
potential energy), or a magnetic field (magnetic potential energy).
Answer #3:
Explanation:
D
Nuclear power is the use of nuclear reactions that release nuclear energy to
generate heat, which most frequently is then used in steam turbines to
produce electricity in a nuclear power plant. The term includes nuclear
fission, nuclear decay and nuclear fusion
Answer #4:
Explanation:
A
The surface area of the Moon is 37.9 million square kilometers. That sounds
like a lot, but it's actually smaller than the continent of Asia, which is only
44.4 million square km. The surface area of the whole Earth is 510 million
square km, so the area of the Moon compared to Earth is only 7.4%.
Answer #5:
Explanation:
A
The Moon orbits Earth at a speed of 2,288 miles per hour (3,683 kilometers
per hour). During this time it travels a distance of 1,423,000 miles
(2,290,000 kilometers).
HighFour General Sciences
Category A: Grades 4 – 5
Round 10
Monday, June 6, 2016
The use of calculator is not allowed.
Answer #6:
Explanation:
A
We orbit the Sun at a distance of about 150 million kilometers. This number
is actually an average, since we follow an elliptical path. At its closest point,
the Earth gets to 147 million km, and at its most distant point, it’s 152
million km.
Answer #7:
Explanation:
A
The acronym "NASA" stands for National Aeronautics and Space
Administration. The term Aeronautics comes from the Greek words for
"air" and "to sail."
Answer #8:
Explanation:
C
On July 29 of 1958, the U.S. Congress passed legislation establishing the
National Aeronautics and Space Administration (NASA), a civilian agency
responsible for coordinating America’s activities in space. NASA has since
sponsored space expeditions, both human and mechanical, that have
yielded vital information about the solar system and universe.
Answer #9:
Explanation:
A
NASA Headquarters, in Washington, provides overall guidance and
direction to the agency, under the leadership of the Administrator. Ten
field centers and a variety of installations around the country conduct the
day-to-day work in laboratories, on air fields, in wind tunnels, and in control
rooms. Together, this skilled, diverse group of scientists, engineers,
managers, and support personnel share the Vision, Mission, and Values
that are NASA.
Answer #10:
Explanation:
D
At any one time, we see only half the moon, and from Earth's surface we
see only the nearside. But, over time, it's possible to see as much as 59% of
the moon's surface, due to a slight north-south rocking and east-west
wobbling of the moon known as lunar libration.
HighFour General Sciences
Category A: Grades 4 – 5
Round 10
Monday, June 6, 2016
The use of calculator is not allowed.
Answer #11:
Explanation:
B
Light is the fastest-moving stuff in the universe. It travels at an incredible
300,000 kilometers (186,000 miles) per second. So, in a year, light travels
far. Stars other than our sun are so far distant that astronomers refer to
their distances not in terms of kilometers or miles – but in light-years.
Answer #12:
Explanation:
C
About 71 percent of the Earth's surface is water-covered, and the oceans
hold about 96.5 percent of all Earth's water. But water also exists in the air
as water vapor, in rivers and lakes, in icecaps and glaciers, in the ground as
soil moisture and in aquifers.
Answer #13:
Explanation:
A
The perihelion is the point in the orbit of a planet, asteroid or comet where
(and when) it is nearest to the sun. It is the opposite of aphelion, which is
where (and when) the orbit of the object is farthest from the sun.
Answer #14:
Explanation:
B
The aphelion is the point in the orbit of an object where it is farthest from
the Sun. The point in orbit where an object is nearest to the sun is called
the perihelion. The word aphelion derives from the Greek words, apo
meaning away, off, apart and Helios (the Greek god of the sun).
Answer #15:
Explanation:
D
The Earth's inner core is the Earth's innermost part and according to
seismological studies, it has been believed to be primarily a solid ball with a
radius of about 1220 kilometers, or 760 miles (about 70% of the Moon's
radius). It is composed of an iron–nickel alloy and some light elements
HighFour General Sciences
Category A: Grades 4 – 5
Round 10
Monday, June 6, 2016
The use of calculator is not allowed.
Answer #16:
Explanation:
D
Potassium is an essential mineral and a major electrolyte found in the
human body. It plays an important role in electrolyte regulation, nerve
function, muscle control, and blood pressure. Potassium is found within all
cells of the body, and its levels are controlled by the kidneys.
Answer #17:
Explanation:
A
Although tooth enamel is the hardest substance in your body -- even
stronger than bone -- it’s still susceptible to tooth decay when exposed to
acids in the mouth. Because enamel is composed of mainly calcium
phosphate, a calcium-rich diet is essential during tooth development.
Answer #18:
Explanation:
B
Iron (Fe) is a mineral needed for hemoglobin, the protein in red blood cells
that carries oxygen. Iron is also needed for energy, good muscle and organ
function. About 70% of the body's iron is bound to hemoglobin in red blood
cells.
Answer #19:
Explanation:
D
Potassium is a mineral that the body needs to work normally. It helps
nerves and muscles communicate.
Answer #20:
Explanation:
D
Potassium also helps move nutrients into cells and waste products out of
cells. A diet rich in potassium helps to offset some of sodium's harmful
effects on blood pressure.