HighFour Physics
Category C: Grades 9-10
Round 8
Wednesday, April 20, 2016
The use of calculator is required.
Question #1
A ray of light in air strikes a slab of glass, as shown in
the figure. Calculate the angle of refraction in the
glass, which has an index of refraction of 1.5. Note
that n1sinθ1= n2sinθ2.
Question #2
What do you call the dimensionless quantity equal to the density of a
substance divided by the density of a standard substance, usually water?
Question #3
How many kilograms of the helium in a balloon, if the volume is 50 m3 and
the specific gravity (relative to air) is 0.14? Note that the density of air at
0°C and 1 atm pressure is 1.293 x 10-3 g/cm3. Round off your answer to 2
decimal places.
Question #4
A ________________ is a motion that moves to-and-fro, usually along a
straight line or along an arc of a circle. There are several examples of these
motions: a raindrop striking a leaf on the tree and the leaf gyrates up and
down, the ticking of a grandfather clock, the clang of a dropped piece of
metal, and the twang of a guitar string.
Question #5
The speed of light in a certain kind of glass is three-fifths as much as in
vacuum. What is the index of refraction of the glass? Round off to 2 decimal
places.
HighFour Physics
Category C: Grades 9-10
Round 8
Wednesday, April 20, 2016
The use of calculator is required.
Question #6
Refer to the figure shown.
What is the average velocity
(m/s) of the train during the
first 50 seconds?
Question #7
What is the horizontal force (in Newton) on a bowling ball that has a mass
of 227 grams, if the bowler gives it a velocity of 6.10 m/s in 0.40 s? Round
off your answer to 2 decimal places.
Question #8
Calculate the kinetic energy of a 25-g bullet moving at 1000 m/s.
Question #9
A certain spring is 30.0 cm long when a load of 40.2 N hangs from it and
37.0 cm long when the load is 45.2 N. What is the force constant (N/m) of
the spring? Round off your answer to 1 decimal place only.
Question #10
How far from a converging lens of focal length of 20 cm should an object be
placed in order to form an image on a screen that is 80 cm from the lens?
Round off your answer to the nearest whole number.
HighFour Physics
Category C: Grades 9-10
Round 8
Wednesday, April 20, 2016
The use of calculator is required.
Question #11
A plane is traveling toward the southwest at 320 km/hr. What is the
eastward component of its velocity?
Question #12
A car travels the length of a turnpike that is 440 km long in 5 hours 30
minutes. What is its average speed in km/hr?
Question #13
A butterfly raises its four wings from horizontal to vertical positions; each
wing is approximately rectangular, 3 cm tall by 4 cm long, of mass 0.020 g.
What is the increase in potential energy (in terms of ergs)? The center of
gravity of each wing is raised by 1.5 cm.
Question #14
A golf ball of mass 60 g is struck by a golf club and acquires a speed of 70
m/s during the impact, which lasts for 2x10-4 s. What force (assumed
constant) is exerted on the ball?
Question #15
What is the maximum force of friction of a 50-kg block resting on a table,
and the coefficient of static friction of 0.30? Express your answer in terms
of Newton.
HighFour Physics
Category C: Grades 9-10
Round 8
Wednesday, April 20, 2016
The use of calculator is required.
Question #16
A spring having force constant of 250 N/m is loaded with a mass of 10 kg.
Find the period of vibration. Correct your answer to 2 decimal places.
Question #17
A force of 200 dyne acting on a body produces an acceleration of 50 cm/s2.
What is the mass of the body in grams?
Question #18
What do you call compression waves of frequencies above about 20000 Hz?
Question #19
Express -328°F in degree Kelvin.
Question #20
Calculate the speed of light in benzene. The index of refraction for benzene
is 1.50. Convert your answer to km/s and round off to the nearest whole
number.