physics circular motion graviation optics

What is a vector?

A vector has size (magnitude) and direction.

What is a scalar?

A scalar has only size (magnitude), no direction.

What is inertia?

Inertia is the tendency of an object to resist a change in its motion.

What is gravity as a property of mass?

Gravity is the force of attraction between objects that have mass.

What is the definition of work?

Work is done when a force moves an object in the direction of the force.

What is a light ray?

A light ray is a straight line that shows the path along which light travels.

Give examples of luminous objects.

The Sun, a lamp, and a candle are luminous objects.

Give examples of illuminated objects.

The Moon, a mirror, and a book are illuminated objects.

How do we see an object?

We see an object when light from it enters our eyes.

What is magnification?

Magnification is how much larger or smaller an image is compared to the object.

What is period?

The period is the time taken for one complete cycle or orbit.

What is frequency?

Frequency is the number of cycles or vibrations per second.

What is angular velocity?

Angular velocity is how fast an object rotates, measured in angles per second.

What is centripetal acceleration?

Centripetal acceleration is the acceleration directed toward the center of a circular path.

What is centripetal force?

Centripetal force is the force that keeps an object moving in a circle toward the center.

What is gravitation?

Gravitation is the universal force of attraction between all masses.

Which force keeps a satellite in orbit around the Earth?

The Earth's gravitational force provides the centripetal force.