Answer:
The correct option is 'd': The change in shape of an object.
Explanation:
Since by definition physical change is defined as a change that changes only the form of an object or substance and producing no change in the chemical composition of the substance. Physical changes are reversible in nature.
As we can see from all the options the change in the shape of the object is a reversible change as we can always remold any substance in any shape, thus it confirms to a physical change.
The change in the molecular composition of an object is a hallmark of a chemical reaction thus indicates a chemical change.
The smell change in an object is an indication of a chemical change in the object hence is not a physical change.
The wave takes 11.3 s to cover a distance of 26.5 m, so its speed is:
The distance between two consecutive crests is 3 m, and this corresponds to the wavelength of the wave. To find its frequency, we can use the relationship between the speed v, the wavelength
and the frequency f:
Answer:
c) curves downward, below the initial velocity vector
Explanation:
A projectile is usually launched from a height, where it is launched with an initial velocity. From that point the gravitational force begins to act on the projectile causing it to decay. As time passes, the projectile advances but its height decreases. So its trajectory is curved downward, below the initial velocity vector.
Simple machines could be used to reduce effort or extend the ability of people to perform tasks beyond their normal capabilities.
Examples include pulley, lever, and incline plane
