Download HighFour Physics Round 5 Category D: Grades 11 – 12 Monday

HighFour Physics
Category D: Grades 11 – 12
Round 5
Monday, January 25, 2016
The use of calculator is required.
Question #1
A team of movers use an inclined plane to get a piano that weighs 3600 N
over a doorstep.
500 N
3.0 m
0.27 m
The plane is 3.0 meters long and the step is 0.27 meters high. If the movers
apply a force of 500 N, what is the efficiency of the plane? Round off your
answer to the nearest whole number.
Question #2
In a radioactive decay process, the ___________ is the time required for
half the nuclei in a sample of a nuclide to make the transition. Identify the
missing word.
Question #3
In a cyclotron, a beam of protons is moving in a circle of radius 0.80 meters.
If an electromagnet supplies a force of 8.00 x 10-13 N directed toward the
center of revolution, what is the velocity of the protons in km/sec? Round
off to the nearest whole number.
Question #4
A rocket of mass 104 kg, starting from rest, is acted on by a
net force of 2x105 N for 20 seconds. What is the final velocity
of the rocket?
Question #5
Two charged bodies exert a force of 16 mN. What will be the force between
the same two bodies if the distance between them is doubled? Write your
answer in terms of mN.
HighFour Physics
Category D: Grades 11 – 12
Round 5
Monday, January 25, 2016
The use of calculator is required.
Question #6
A square loop of wire 4 cm on an
edge is lying on a horizontal table.
An electromagnet above and to
one side of the loop is turned on,
causing a uniform magnetic field
that is downward at an angle of 30°
from the vertical as shown in the
figure.
The
magnetic
field
2
induction, B, is 0.500 Wb/m .
30°
Calculate the magnetic flux, Φm in terms of Wb. Express your answer in
scientific notation, accurate to 2 decimal places only.
Question #7
Four hundred grams of lead BB shot is heated to 100°C and dropped in a
100-g glass beaker containing 200 grams of water at 20°C. The specific hear
of glass is 0.20 . The mixture is stirred until temperature equilibrium is
24.2°C. What is the specific heat (in
) of lead?
Question #8
The specifications of a certain hi-fi turntable call for it to reach its final
angular velocity of
rev/min while turning through rev, starting from
rest. What is the angular acceleration of such a table? Express your answer
in rev/s2, accurate to 3 decimal places.
Question #9
A house air conditioner moves heat from a coil at 13°C to the outside
environment at 32°C. Calculate the coefficient of performance (COP) of the
air conditioner. Round off to the nearest whole number.
Question #10
In electrolysis, how much charge is required to deposit or liberate one
gram-equivalent of any substance?
HighFour Physics
Category D: Grades 11 – 12
Round 5
Monday, January 25, 2016
The use of calculator is required.
Question #11
A 37-kg girl is sitting in a swing. What force (F), applied
horizontally, will hold the swing and the girl out at an
angle of 30° with the vertical? Answer in terms of Newton
and round off to the nearest whole number.
Question #12
The first law of thermodynamics is concerned with the conservation of
______________. Identify the word by writing the correct answer.
Question #13
If the speed of sound in a certain gas is 360 m/s at 250°C, what is the speed
of the same gas at 500°C? Write your answer in terms of m/s, accurate to 1
decimal place only.
Question #14
A boy on a bicycle is travelling at 10.0 m/s. What is the angular speed of a
point on the tire of the bicycle, if its radius is 34.0 cm? Supply your answer
with 1 decimal place only and with the appropriate unit.
Question #15
A fire hose sends 900 kg of water every minute against a burning building.
The water strikes the building with velocity 25 ms and does not bounce
back. What force does the building exert on water? Note: Be careful to affix
the proper sign, + or -, and unit to your answer.
HighFour Physics
Category D: Grades 11 – 12
Round 5
Monday, January 25, 2016
The use of calculator is required.
Question #16
A roller coaster car of mass
3500 kg proceeds from point A
to point B then to point C. How
much potential energy did the
car lose in going from A to C?
(30m high) A
C (10m high)
B
Question #17
How much charge flows through the bulb in a student’s desk lamp in 1 hour
if the current through the bulb is 0.4 A? Express your answer in Coulombs.
Question #18
A ________________ exists in any region of space where a moving electric
charge would experience an electric force other than Coulomb force. It can
be explored by using a moving charge as a test body. Identify the missing
word/s.
Question #19
A 2000-cm3 quartz beaker is brimful of turpentine at a room temperature
of 20°C. If the beaker and the contents are put in a refrigerator so that the
temperature becomes 5°C, what is the volume of the turpentine (β = 900 x
10-6 °C-1)?
Note: Ignore the expansion of the quartz beaker since its coefficient is so
small.
Question #20
Henry Cavendish performed experiments to validate the
gravitational force of attraction between two bodies. It
was during one of his experiments that he determined the
mass of the earth. He considered a 1-kg object at the
surface of the earth. Determine the ratio of the masses of
the earth to the sun if the sun’s mass can be approximated
at 2x1030 kg and the radius of Earth is 6.4x106 meters.
Express your answer in scientific notation.