7TH GRADE PRACTICE
Physics Problems: Mass and density, Grade 7
Inertia, mass, volume and density of matter.
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 #19
Inertia, interaction and massEvaluate the statement: The phenomenon of conservation of body speed when external influences are absent or mutually balanced.
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The cart does not stop instantly on its own: its speed is changed by frictional forces and air resistance.
Answer
Problem #20
Inertia, interaction and massEvaluate the statement: the concept “Interaction of bodies” means: A physical quantity that characterizes the inertia of a body and serves as a measure of the amount of matter at the school level.
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After the collision, both carts change motion, although the changes may be different due to the difference in mass.
Answer
Problem #21
Mass and inertiaTwo free carts are subjected to equal forces for the same amount of time. The first one changed the speed less. Which conclusion is correct?
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Answer
Problem #22
Volume and density of matterEvaluate the statement: A physical quantity showing the portion of space occupied by a body or substance.
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The volume of a rectangular bar is determined by its dimensions, and the volume of a body of complex shape is determined by the displaced liquid.
Answer
Problem #23
Volume and density of matterEvaluate the statement: the concept “Table of Densities” means: A physical quantity equal to the mass of a unit volume of a homogeneous substance.
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Before comparison with the table, convert mass and volume into agreed units and take into account the state of aggregation of the substance.
Answer
Problem #24
DensityThe mass of a homogeneous part is 540 g, and its volume is 200 cm³. Find the density of the part.
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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.