Transcript physics-_staar_prep_2_25_practice_quesitons.pptx

PHYSICS- STAAR
PREP 2
20 PRACTICE QUESITONS
Question 1

Two electrically charged, hollow aluminum spheres of the same mass, size and charge
are pictured below. If both are on a hard, flat table in close proximity to each other
what is the most probable result?
Sphere 1
Negative Charge of 1
Sphere 2
Negative Charge of 1

a. Both spheres will roll towards each other at the same initial rate of acceleration,
and as they get closer to each other the acceleration will increase.

b. Both spheres will roll away from each other at the same initial rate of acceleration,
and as they get further apart the acceleration will decrease.

c. Both spheres will roll away from each other at the same rate of acceleration, and as
they get further apart the acceleration will continue at the same rate.

d. Both spheres will roll towards each other at the same initial rate of acceleration,
and as they get closer to each other the acceleration will continue at the same rate.
Answer 1
 b. Both spheres will roll away from each
other at the same initial rate of
acceleration, and as they get further apart
the acceleration will decrease.
Question 2
 Two unlike electrically charged particles are located a certain
distance away from each other. If the distance between the two is
reduced by half, what will happen to the forces between the two
particles?

a. the two particles will attract, and the forces of attraction will
quadruple.
 b.The two particles will attract, and the forces of attraction will
double.
 c.The two particles will repel, and the forces of repulsion will
quadruple.
 d.The two particles will repel, and the forces of repulsion will double.
Answer 2
 a. the two particles will attract, and the
forces of attraction will quadruple.
Question 3
 A force can exist between two objects without
those objects being in contact. What force is at
work when a ball tossed into the air falls back to
Earth?
 a. gravitational force
 c. electrical force
b. buoyant force
d. magnetic force
Answer 3
 a. gravitational force
Question 4
 The gravitational force between objects depends
upon several factors. How would the gravitational
attraction between two objects change if the mass
of one of the objects decreased?
 a. The gravitational attraction would not change.
 b.The gravitational attraction would increase.
 c.The gravitational attraction would decrease at first,
then increase.
 d.The gravitational attraction would decrease.
Answer 4
 d.
 The gravitational attraction would decrease
Question 5
How would the gravitational force change if the
distance between the objects increased?
 a.The force would fluctuate randomly.
 b.The force would increase.
 c.The force would decrease.
 d.The force would not change.
Answer 5
 c. The force would decrease
Question 6
 From which planet shown in the table would
an object have to move farthest to become
weightless?
Planet
Mass
 B. Earth
Mercury
3.302 x 1023
 c.Venus
Venus
4.869 x 1024
Earth
5.974 x 1024
Mars
6.419 x 1023
 a.Mercury
 D. Mars
Answer 6
 B. Earth - has the largest mass
Question 7
 Which planet shown in the table would have
the least gravitational attraction for an object
on its surface?
 a.Venus
Planet
Mass
 B. Mercury
Mercury
3.302 x 1023
 c.Mars
Venus
4.869 x 1024
Earth
5.974 x 1024
Mars
6.419 x 1023
 D. Earth
Answer 7
 B. Mercury
Question 8
 The picture below shows three electrically charged particles. The
center particle is equidistance away from the outer two particles.
Which diagram most accurately depicts the relative
electromagnetic forces resulting from the amount of charge on each
particle?
1 Negative
3 Positive
3 Negative
 ______________________________________
1 Negative
1 Negative
3 Positive
3 Positive
3 Negative
3 Negative
1 Negative
3 Positive
3 Negative
Answer 8
1 Negative 3 Positive 3 Negative
Question 9
 Two electrically charged particles are moved closer to each other.
Attractive forces between the particles are detected to be getting
stronger and stronger as the particles move closer together. What
can be determined about the two particles?
 a. The particles are of like charge.
 b.T he particles are of unlike charge.
 c. The particles are rotating around each other as in an
orbit.
 d. The two particles are both electrons.
Answer 9
 b. T he particles are of unlike charge.
Question 10
 How would the gravitational force change if
the objects moved closer together?
 a. The force would not change.
 b.The force would decrease.
 c.The force would fluctuate randomly.
 d.The force would increase.
Answer 10
 d.The force would increase.
 How would the gravitational attraction




between two objects change if the mass of
both objects increased?
a.The gravitational attraction would increase.
b.The gravitational attraction would not
change.
c.The gravitational attraction would decrease.
d.The gravitational attraction would increase
at first, then decrease.
Answer 11
 a.The gravitational attraction would increase.
Question 12
 What would occur between the spheres below?
Net Positive Charge
Net Positive Charge
 a.Both spheres will have a net force of zero on them, and will not
move.
 b.Both spheres will have forces attracting each other and will roll
towards each other.
 c.Both spheres will have forces opposing each other and will roll
away from each other.
 d.Both spheres will have a net force directed towards the right and
will both move to the right.
Answer 12
 c.Both spheres will have forces opposing
each other and will roll away from each
other.
Question 13
 Which change would increase the total current, I, flowing
through this circuit?

A increasing the voltage of the battery

B decreasing the length of the wires

C rewiring the two resistors in a series

D adding a third resistor in parallel
Answer 13
 D adding a third resistor in parallel
Question 14
 Calculate the total resistance of the following
circuit.
Answer 14
 4.8 ohms
Question 15
 What is the total current in the circuit?
Answer 15
 5 amps
Question 16
 In order to make a stronger electromagnet,
which one of the following is effective?
 A use more turns (wraps) of wire
 B use an iron core instead of a wooden core
 C use more current through the wire
 D All of the above are correct.
Answer 16
 D –all of the above
Question 17
 A 12.0 volt battery is connected to 4 identical
3.00 ohm resistors connected in parallel to
each other. What is the current in the circuit?

Answer 17
 16 amps
Question 18
 In the water flow analogy, the current in a
circuit is analogous (same as) to —
 A the water pipes.
 B the water pump.
 C the on/off valve.
 D the water.
Answer 18
 D -The water
Question 19
 Two electrically charged particles are moved closer to each other.
Repelling forces between the particles are detected to be getting
stronger and stronger as the particles move closer together. What
can be determined about the two particles?
 a.The particles are of like charge.
 b.The particles are of unlike charge.
 c.The particles are rotating around each other as in an orbit.
 d.The two particles are an electron and a proton.
Answer 19
 a. The particles are of like charge.
Question 20
 Angie weighs 380 Newtons. She is carrying a
25.6-newton backpack. She climbs the stairs
in her school from the first floor to the second
floor, a height of 2.9 meters. How much work,
in joules, has Angie done?
Answer 20
 1176 joules
Question 21
 A ball is thrown down at a speed of 3.0 m/s
and accelerates under the pull of gravity for
2.0 seconds. How fast is it moving?
 A. 6 m/s
 B. 23 m/s
 C. 18m/s
 D. 6m
Answer 21
 B. 23 m/s
Question 22
 A rubber ball strikes the ground with a
downward force of 12 N. According to
Newton’s third law, how much force does the
ground exert on the ball?
Answer 22
 12 N Upward
Question 23
 A metal ball has a momentum of 12 kg.m/s
southward. If the ball has a velocity of 3m/s,
what is the mass?
Answer 23
 4 kg
Question 24
 A dart with a mass of 50 g is thrown at 15 m/s
and sticks into a 100 g apple hanging on a
string. What is the velocity of the dart and
apple just after the dart is embedded?
Answer 24
 5 m/s
Question 25
 Air bags help to minimize injuries by providing a
large area for the force of impact to be exerted.
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
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
In terms of the impulse-momentum theory, what
is another advantage of an air bag?
A. decreases the momentum of the passenger
B. Increases the amount of time the force is
applied
C. Decreases the net force applied by the air bag
D Increases the impulsive force applied to the
passenger
Answer 25
 B. Increases the amount of time the force is
applied