The area under a velocity-time graph gives which quantity?
- A.Acceleration
- B.Displacement
- C.Force
- D.Momentum
Correct answer
Explanation
The correct answer is B, displacement. On a velocity-time graph the height of the curve is velocity and the base is time, so the area enclosed is velocity multiplied by time, which is displacement.
Option A, acceleration, is given by the slope of the same graph, not by its area, and mixing up slope and area is the commonest error in this question. Option C, force, and option D, momentum, cannot be read off a velocity-time graph at all unless the mass of the body is also given. The companion result is worth learning in the same breath: on a distance-time graph the slope gives the speed, so a straight sloping line means uniform speed and a horizontal line means the body is at rest. Papers often show a simple graph and ask for one of these three readings.
Read the full article: Motion, Force and Newton's Laws: Formulas and Facts
Practice Questions
View allNewton's first law of motion is also known by which name?
- A.Law of inertia
- B.Law of momentum
- C.Law of action and reaction
- D.Law of gravitation
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The first law states that a body continues in its state of rest or of uniform motion in a straight line unless an unbalanced external force acts on it, which is exactly the property called inertia.
Read the full explanation →Which of the following is a vector quantity?
- A.Distance
- B.Speed
- C.Displacement
- D.Time
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It is the shortest distance from the starting point to the finishing point together with the direction of that straight line, so it has both magnitude and direction and is therefore a vector.
Read the full explanation →The equation force equals mass multiplied by acceleration follows from which law of motion?
- A.First law
- B.Second law
- C.Third law
- D.Law of conservation of energy
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It states that the rate of change of momentum of a body is proportional to the applied force and takes place in the direction of the force.
Read the full explanation →The recoil of a gun when a bullet is fired is explained by the conservation of which quantity?
- A.Energy
- B.Linear momentum
- C.Mass
- D.Electric charge
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Before firing, the gun and the bullet are at rest, so the total momentum of the system is zero.
Read the full explanation →What is the SI unit of momentum?
- A.Newton
- B.Joule
- C.Kilogram metre per second
- D.Newton per second
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Momentum is the product of mass and velocity, so its unit is the unit of mass multiplied by the unit of velocity, that is kilogram multiplied by metre per second.
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