PS 03.3 Inertial Frames and Relative Motion

Which of the following best describes a frame of reference?

• A system for specifying the precise location of objects in space and time.

• A type of force acting on an object.

• A method for measuring temperature.

• A device used to measure speed.

What is an inertial frame?

• A frame of reference that is not accelerating.

• A frame of reference that is always moving.

• A frame of reference attached to a rotating object.

• A frame of reference used only in astronomy.

If a car moves at 60 km/h east and another car moves at 40 km/h east, what is the relative velocity of the first car with respect to the second?

• 20 km/h east

• 100 km/h east

• 20 km/h west

• 60 km/h west

A boat is moving north at 5 m/s in a river flowing east at 3 m/s. What is the magnitude of the boat's velocity relative to the ground?

• 5.83 m/s

• 8 m/s

• 2 m/s

• 3 m/s

Why is it important to consider frames of reference when solving problems involving motion?

• Because motion can appear different depending on the observer's point of view.

• Because all objects move at the same speed.

• Because time is always constant.

• Because forces do not affect motion.

Which of the following best defines an inertial frame?

• A reference frame in which the observers are not subject to any accelerating force.

• A frame where all objects are at rest.

• A frame that always moves with constant velocity.

• A frame that is always accelerating.

What is a reference frame?

• A coordinate system or set of axes within which to measure the position, orientation, and other properties of objects in it.

• A device used to measure time.

• A tool for measuring temperature.

• A type of force acting on an object.

Relative velocity is defined as:

• The vector difference between the velocities of two bodies.

• The sum of the velocities of two bodies.

• The product of the velocities of two bodies.

• The average velocity of two bodies.

If an observer is in a reference frame that is accelerating, is it considered an inertial frame?

• No, because an inertial frame is not subject to any accelerating force.

• Yes, because all reference frames are inertial.

• Yes, if the acceleration is constant.

• No, only if the frame is at rest.

Why is the concept of a reference frame important in physics?

• It allows measurement of position, orientation, and other properties of objects.

• It determines the color of objects.

• It is used to calculate temperature.

• It is only used in chemistry.