9TH GRADE PRACTICE
Physics Problems: Kinematics, Grade 9
Coordinates, vectors, graphs, acceleration and circular motion.
Here the conditions and analysis of the solution can be read without an account. In the simulator, you need to collect the same analyzes yourself: “Given,” formulas, order of steps and answer.
Problem statements
The answer options are there to check against, and the walkthrough opens under each problem.
Problem #1
Frame of reference and uniform motionEvaluate the statement: A model of a body whose size and shape can be neglected when solving the chosen problem.
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A car can be considered a point on a long highway, but not when analyzing its parking in a cramped garage.
Answer
Problem #2
Frame of reference and uniform motionEvaluate the statement: the concept of “Displacement and projection” means: The dependence of coordinates on time allows you to predict position and build a motion graph.
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Projection can be positive, negative or zero; the path remains a non-negative trajectory length.
Answer
Problem #3
KinematicsThe body begins to move from point x₀ = -10 m with a constant velocity projection of 4 m/s. Find the coordinate after 5 s.
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Answer
Problem #4
Uniformly accelerated motion and its graphsEvaluate the statement: The speed of the body at a given time, directed tangentially to the trajectory.
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The average ground speed is equal to the distance over time, the average speed of movement is related to the movement vector, and the speedometer shows the instantaneous module.
Answer
Problem #5
Uniformly accelerated motion and its graphsEvaluate the statement: the concept “Graphical methods of kinematics” means: Movement in which the velocity vector changes equally over equal periods of time.
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The slope of the velocity graph is equal to the acceleration, so the sign of the slope indicates acceleration or a change in speed in a negative direction.
Answer
Problem #6
KinematicsThe initial speed of the body is 2 m/s, acceleration is 3 m/s², acceleration time is 4 s. Find the final velocity and displacement.
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Answer
Problem #7
Free fall, circle and relativityEvaluate the statement: Movement with a constant velocity magnitude, but a continuously changing direction of the velocity vector.
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Centripetal acceleration is directed towards the center and is responsible precisely for the rotation of the velocity vector.
Answer
Problem #8
Free fall, circle and relativityEvaluate the statement: the concept of “Free fall” means: The speed of a body depends on the reference system and adds up to the portable speed of the selected system.
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In one place, all bodies receive the same g; it is measured by the time and path of fall or by the period of the pendulum with an estimate of the error.
Answer
Problem #9
Circular movementA car passes a circular turn with a radius of 20 m at a speed of 10 m/s. Find the centripetal acceleration.
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Answer
The theory behind these problems
Work through the topic if a problem will not give in.
Formulas by topic
Look up symbols and units of measurement in the reference.