Science Review
A rock with a mass of 2 kg has a weight of 40.8 N on the moon. What is the value of the acceleration of gravity (g) on the moon?
1.6 m/s^2.
Four forces act concurrently on a point as shown above. The resultant displacement of the runner is
10 meters north
One kilogram of mass has a weight of about 2.2 pounds. The weight of 50.0-kilogram Rottweiller expressed is pounds is
110.
Three forces acting on an object as shown in the diagram. The object is not moving. Two forces are 2 newtons and 10 newtons. The third force is
12 newtons.
What is the surface area of the box in Figure 1-1A?
120cm^2
Which of the following launch angles will give a projectile the same range?
15 degrees and 75 degrees
The acceleration of gravity on the moon is about 1.6 m/s^2. A 2 kilogram object on the moon is dropped from rest. After ten seconds, the speed of the object is
16 m/s.
From home, you walk 6 blocks East and then 4 blocks West. Your distance from home is
2 blocks.
A 1 kg mass is suspended from spring that has a spring constant of 5 N/cm. The spring stretches by about
2 centimeters.
An object is observed to have an acceleration of 2 m/s^2 when a net force of 4 newtons applied. The mass of the object is
2 kilograms.
The initial speed (v0) shown in Figure 4-3 is
2.0 m/s.
The weight of a certain car is approximately 2,350 pounds. The weight expressed scientific notation is
2.35x10^3.
Using scientific notation, the ratio 3.2/1,280 is written as
2.5x 10^-3.
What is the length of the object pictured next to the metric ruler?
2.60 centimeters.
A water balloon is launched horizontally at a height of 1.5 meters above the ground. Its launch speed is 30 m/s/ the instant before the balloon hits the ground, its horizontal speed is
20 m/s.
According to Figure 4-2, int the first 5 seconds the object moves a distance approximately
20 meters.
A rocket sled accelerates from 10 m/s to 50 m/s in 2 seconds. What is the acceleration of the sled?
20m/s^2.
A golfer hits the golf ball at a 35 degrees angle at a speed of 37 m/s. The maximum height to which the ball travels is about
21 meters
A stone is dropped from the roof of a tall building. A person measures the speed of the stone to be 49 m/s when it hits the ground. The height of the building is closest to
24 meters.
An electronic clock gives the elapsed time 7:34:21. How many seconds does this represent?
27,261.
If an automobile travels at 30 m/s for 2 minutes, how far has the car traveled?
3,600 m.
If the average speed of a drag racing car is 0.069 miles per second, how long would it take the car to complete a 1/4 mile (0.25 mile) straight track?
3.6 seconds.
What is the speed of a jet plane that travels 3,000 meters in 10 seconds?
300 m/s.
A clever person who knows physics measures the depth of a deep hole by dropping rock into the hole. The rock takes 3.2 seconds to hit the bottom. The depth of the hole is approximately
31 meters.
The approximate number of days in one year is 365.25. The number of seconds in one year is
31,558,000.
The acceleration of gravity expressed in English units is
32.2 ft/s^2.
A 1 kilogram block is placed on each of the four frictionless ramps inclined at different angles as shown in the diagram below. Which block will experience the greatest acceleration?
4
As ports car reaches a speed of 50 m/s in 12 seconds after starting from rest. The acceleration of the car is
4.17 m/s^2.
In 1/2 hour, a bicyclist traveled 20 kilometers. What was the bicyclist's average speed?
40 km/h.
A projectile is launched at which angle will have the greatest range?
45 degree
Projectile travel the greatest distance horizontally when the launch angle is
45 degree
How fast must an object be thrown upward if it is to stay in the air for 5 seconds before hitting the ground again?
49 m/s.
An aircraft accelerates st 49 m/s^2. Express he acceleration in multiples of the acceleration of gravity (g).
5 g's.
A car goes from 30 miles per hour (mph) to 60 mph in six seconds. The acceleration of the car is
5 mph per second.
If scientific notation were used to represent the number 5,280, it would be written
5.280x10^3.
Use a Figure 4-1A to choose which of the following would be the best prediction of the avocado tree's height when it is 10 years old?
5.5 m.
Which of the four graphs in Figure 4-4 shows motion at constant speed for 2 seconds followed by constant acceleration for two seconds?
A.
Vector quantities are represented by arrows. If two vector arrows are combined, the vector that represents their sum is called the
Resultant
An ice skater feels very little force as she moves in a straight line on her skates. According to Newton's first law, which of the following statements about her motion is TRUE?
She must apply force with her skates to turn or stop.
An example o a scalar quantity is
Speed
The equation v=v0+at relates which tree variables?
Speed, acceleration, and time.
What type of relationship do the variables have in the graph in Figure 4-1A?
Strong relationship.
Two projectiles are launched at different angles. One is launched at 30 degrees and the other at 60 degrees. Which statement is true ?
The 60 degrees projectile has a greater vertical component of velocity than the 30 degrees projectile.
If every force has an equal and opposite reaction why don't all forces cancel out with each other?
The action and reaction forces act on different objects.
If every force has an equal and opposite reaction, why don't all forces cancel out with each other?
The action and reaction forces act on different objects.
Which of the following is not true about an action-reaction pair of forces?
The action force is applied first and the reaction force appears later.
The term "at" in the equation v=v0+at represents
The amount the object's acceleration has changed.
A race car rounds a curve on the track at a constant speed of 180 mph. Is the car accelerating?
Yes, its direction is changing.
If an object changes its direction of motion
a force must have been applied to the object.
If the speed is constant, which variable is zero in the equation x=x0+v0t+1/2at^2?
a.
The rate at which velocity changes is called
acceleration.
What is the independent variable for the graph in Figure 4-1A?
age.
The newton is a unit of force that is defined by
an acceleration of 1 m/s^2 of an object with a mass of 1 kilogram.
According to Hooke's law:
an object resist being stretched with a force equal to the spring constant multiplied by the change in length by which the object is stretched.
Force is best defined as
any action that could change the motion of an object.
Speed that does not change is called
constant speed.
Selina drops a golf ball down deep well. The ball falls with only the force of gravity acting on it. Without any air resistance, as the golf ball in Figure 4-2A falls into the well, its acceleration is
constant.
If no forces are acting on an object, its motion will
continue in the same direction with the same speed.
The equation which correctly represents the relationship between speed, distance, and time is
d=vxt
The most appropriate unit of time for measuring the period from last Friday to next Wednesday is the
day.
Many cars are made with an automatic feature called cruise control. When the driver sets a car on cruise control, a computer adjusts the engine to maintain the car's speed constant. When a car is on cruise control on a straight road, the acceleration of the car is the best described as
equal to zero.
Compared to a 1 kilogram chunk of iron, a 1 kilogram piece of Styrofoam
takes up more space.
When you kick a ball, your foot feels the ball because:
the ball exerts a force on your foot as a reaction to the force of your foot on the ball.
A boy on a skateboard throws a ball. The skateboard moves in the opposite direction from the thrown ball because
the ball exerts a reaction for force on the boy as it being thrown.
When constructing a graph, the x-axis is most closely related to
the independent variable.
The force of dry sliding friction increases when
the normal force that opposes motion.
In physics, the term free fall means
the object is dropped from an initial speed of zero.
If large changes in the independent variable cause small changes in the dependent variable
the relationship is weak.
Two object have the same inertia if
the same force causes the same acceleration in both objects.
Two objects have the same inertia if
the same force causes the same acceleration in both objects.
If the net force is negative and the speed is positive
the speed will decrease over time.
The graph shows the motion of an object moving in a straight line. From the graph, you may conclude that
the total force acting on the object is zero.
Soft materials like rubber can have a very high coefficient of friction because
they conform to surfaces and create many points of contact.
Ball bearings decrease friction because
they replace sliding motion with rolling motion.
Three forces act on the cart shown in the diagram. The acceleration of the cart is
to the left at 2 m/s^2.
Variables like velocity and acceleration that have both size and direction are called
vectors.
Viscous friction occurs when
wet surfaces slide over each other.
Dependent variable is on the
y-axis.
A ball with a mass of 1 kilogram is moving at the same speed as a ball with a mass of 10 kilograms. Which of the following statements correctly compares the force required to stop each of the two balls?
It takes more force to stop the 10 kilogram ball because the 10 kilogram ball has more inertia.
On a graph, all of the following directions are normally considered to be positive except?
Left.
Which one of the following is not true concerning mass and weight?
Mass is measured in newtons and weight is measured in pounds.
Which is a good example of a gas at normal room temperature?
Oxygen.
The smallest measurable length of a centimeter stick is 0.001 cm. Which of the following best describes this limit?
Precision.
A plane flies 200 km West and then flies 300 km South. Its new position is
-200 km, -300 km.
A car is traveling at 30 m/s in a straight line. The driver applies the breaks for 3 seconds, and the car slows down to 12 m/sec. The acceleration of the car is
-6 m/s^2.
A force of 10 lbs is applied to a wagon that weighs 100 lbs. The acceleration of the wagon is closest to
0.1 m/s^2.
The graph in Figures 4-3 shows an acceleration of
0.2 m/s^2.
A force of 5 N is required to slide a block at constant speed over the dry surface of a table. The block has a mas of 2.5 kg. The coefficient of sliding friction is
0.2.
Calculate the speed of the object from the position vs. time graph shown below.
0.5 m/s
A bunch of bananas weighs 1.5 lbs on the scale at the grocery store. The mass of the bananas is
0.68 kilogram.
The engine of a rocket accelerates fuel backward to push the rocket forward. The mass of the rocket is 10, 000 kilograms. The rocket engine accelerates 10 kilograms of fuel backward at 1,000 m/s^2. The forward acceleration of the rocket is
1 m/s^2.
A 0.25 kilogram ball is observed to accelerate at 4,000 m/s^2 as it is hit with a bat. How much force is exerted on the bat by the ball?
1,000 newtons.
The acceleration of gravity on the moon is about 1.6 m/s^2. An experiment to test gravity compares the time it takes objects to reach a speed of 10m/s after being dropped from rest. How long does an object dropped on the moon have to fall compared to an object dropped on Earth?
6.1 times as long.
A flock of Canada geese are flying at 41 miles per hour headed due to south. If a 52 mile per hour east wind were to begin blowing, the resultant velocity of the flock would become approximately
66 mph
A 5 newton fierce directed north and a 5- newton force is directed west both act on the same point. The resultant of these two forces is approximately
7 net=tons northwest
What is the volume of the box figure 1-1A?
72 cm^3
Two balls are kicked upwards from the ground at an angle 45 degrees from the horizontal. One ball has a speed of 5 m/s, and the second ball has a speed of 15 m/s. (assume no air friction.) Compared to the slower ball, the faster ball will travel
9 times faster
An object falls for 2 seconds after being dropped from rest. Its speed is approximately
9.8 m/s.
The weight of a 1 kg mass is
9.8 newtons.
A graph can be described as
All of the above (a mathematical diagram, a scientific model, a way to show relationship between variables).
Speed is
All of the above.
The conversion factor for changing one unit of length to another in the English system may be
All of the above. (3, 12, 5280)
Which of the following situation MUST have a net force?
An object accelerates from 1 m/s^2.
Which of the following statements CANNOT ever be true?
An object can have speed that is changing and still have zero acceleration.
A ball is thrown straight up in the air. As the ball travels upward, which diagram correctly shows the net force, speed, and acceleration?
B.
Which of the four graphs in Figure 4-4 shows motion in which an object moves 6 meters?
B.
Which point on the speed versus time graph in Figure 4-1 has the highest acceleration?
B.
An experiment compares the time it takes to accelerate two carts from 1 m/s to 2 m/s. Different amounts of force are tested. The table below lists the result of the experiment. What conclusion is supported by the result of the experiment?
Cart #1 has half the mass of cart #2.
A single force can be represented by two forces (Fx and Fy) at right angles to each other. Two forces (Fx and Fy) are called __________ forces.
Component
When a projectile is launched, the velocity may be described as
Constant in the horizontal direction
An example of a vector quantity is
Velocity.
Tom and Frank shoot water balloons using new launcher Tom received for his birthday. The package claims it will launch balloons up to 200 yards. The boys launch balloons at various angels to determine the angle that makes the balloons travel the greatest distance. If they were graph their results, how would the values be placed on the graph?
Distance on the y-axis, angle on the x-axis.
The acceleration of an object is
Equal to the force acting on the object divided by the mass of the obejct.
What action must be taken to change the motion of an object?
Force must be applied to the object.
Which force always opposes the motion of an object?
Friction
Which if the following statement about friction is not true?
Friction occurs between two objects are at different potential energies.
As the launch angle of a projectile is increased from an angle of 0 degrees to an angle of 90 degrees, the range of the projectile will
Increase then decrease
Which of the following statements gives the best definition of position?
It is variable that gives location relative to an origin.
A basketball player with a mass of 70 kilograms jumps upward by pushing against the floor with his feet with a force of 1,200 newtons. Which is the best explanation for why the basketball player moves upward?
The floor pushes back upward on the player with a force of 1,200 newtons, which lifts the player off the ground.
The normal forces is
The force acting perpendicular to the surface
A quantity whose measurement includes both size and direction is a
Vector
Consider the motion of an object acted on by a net force. Which of the following describes a situation that is possible?
The net force is positive, and acceleration and speed are also positive.
A person on water skis is being towed behind the boat at constant speed. Which statement best describes the situation?
The person is in equilibrium because friction from the water creates a force equal and opposite to the force from the boat.
Which of the following could be considered control variables?
The skateboard. the distance rolled.
Which of the following situations can NEVER happen because it represents a violation of Newton's first law?
The speed of an object changes even though no forces are acting on the object.
Which of the following statements about the graph in Figure 4-1 is FALSE?
The speed of the car is constant at point D.
A friend tells you that a different size of ball bearing might make your skateboard move faster. You try three different sizes and keep track of the time to roll 50 feet. You write down exactly how you tried the ball bearings on your skateboard and make a chart of time it took to roll te 50 feet for each size ball bearing. The size of the ball bearing is
experimental variable.
The force called weight comes from
gravity.
The same engine is placed in a large truck and a small car. The engine produces the same amount of force between the vehicle and the road in bot cases. The truck
has a smaller acceleration than the car because the truck has a greater mass.
A cart is rolling down a ramp. If the angle of the ramp is increased to make the ramp steeper, the cart will
have greater acceleration.
What is the dependent variable for the graph in Figure 4-1A?
height.
In which situation would a bicycle rider not be accelerating?
if her direction and speed were unchanged.
Between two and three seconds, the speed of the object shown in Figure 4-2
increases from 1 m/s to 4 m/s.
Without any air resistance, as the golf ball in Figure 4-2A falls into the well, its speed is
increasing.
The measure of mass when it is thought of as a resistance to change in motion is called
inertia.
The unit of force comes from Newton's second law (F=ma). in the metric system, the units for force are
kg m/s^2
Which of the following correctly describes the role of mass in Newton's second law?
mass is measure of the amount of matter in an object.
The inertia of an object comes from its
mass.
Your normal stride as you walk or run would most closely approximate a
meter.
The metric unit of length closest to the thickness of a toothpick is the
millimeter.
A block with a mass of 1 kg sits on a smooth, dry, level surface. The coefficient of static friction is 0.2. The coefficient of dry sliding friction is 0.1. A force of 1.5 N is applied to the block. The block will
remain motionless on the surface.