Physics End of Years y8

How does mass differ from weight when traveling between Earth and the Moon?

Mass stays constant as the amount of matter , while weight changes because the gravitational pull ($g$) is different.

Why does a higher frequency change our perception of a sound wave?

Frequency determines pitch; more vibrations per second result in a higher-pitched sound.

How does the massive speed difference between light and sound affect our observation of a storm?

We see lightning instantly because light travels at $300,000,000 m/s$, while thunder arrives later at only $\sim340 m/s$.

Why does light bend "towards the normal" when it enters a glass block from the air?

Light slows down as it enters a denser medium (refraction), causing its path to bend toward the perpendicular line.

How do we perceive an object as being the color "Red"?

The object reflects red light into our eyes while absorbing all other colors of the spectrum.

Why are electrons the only particles that move when an insulator becomes statically charged?

Electrons are on the outer shells and can be transferred via friction, while protons are fixed inside the nucleus.

How does "Upthrust" determine if a hot air balloon will rise?

If the upward force (upthrust) exceeds the total weight of the balloon, it creates an upward resultant force.

Why does an object in equilibrium (Zero Resultant Force) not necessarily mean it is stationary?

It could also be moving at a constant velocity, as there is no unbalanced force to change its speed or direction.

How does "Terminal Velocity" reach a state where a skydiver stops accelerating?

As the diver speeds up, air resistance increases until it exactly equals their weight, making the resultant force zero.

Why is "Soft Iron" used as the core of an electromagnet?

It is a material that can be magnetized and demagnetized easily, allowing the strength of the magnet to be controlled.

How can the strength of an electromagnet be increased for heavy lifting?

By increasing the electrical current, adding more coils to the solenoid, or using a soft iron core.

How do shadows provide evidence that light travels in straight lines?

They are formed when an opaque object blocks light rays, creating a dark area where the light cannot bend around the object.

Why does a prism cause white light to disperse into a rainbow (ROY G BIV)?

Different wavelengths of light refract by different amounts; red light has the longest wavelength and refracts the least, while violet refracts the most.

How does a red filter change the appearance of white light?

The filter only allows its own color (red) to pass through, absorbing all other colors in the spectrum.

Why is "Soft Iron" specifically chosen for the core of an electromagnet?

It is a material that can be magnetized and demagnetized easily, allowing the magnet to be turned on and off effectively.

How does the "Right-Hand Grip Rule" help predict a magnetic field?

If your thumb points in the direction of the current, your curling fingers show the direction the magnetic field lines follow.

Why does an object reach "Terminal Velocity" instead of accelerating forever?

As speed increases, air resistance (drag) also increases until it exactly equals the object's weight, making the resultant force zero.

How does opening a parachute lead to a safe landing speed?

It drastically increases surface area, maximizing drag to create an upward resultant force that causes the diver to decelerate to a new, slower equilibrium.

Why is the "Normal Reaction Force" essential for a camel standing on a road?

It provides the upward repulsive force that exactly balances the camel's weight, keeping the resultant force at zero so the camel doesn't accelerate into the ground.

How can you tell which part of an electric field is the strongest?

By looking at the field lines; where the lines are closer together, the electric field is at its strongest.

Why do insulators gain a static charge through friction but conductors usually don't?

In insulators, electrons are transferred and trapped on the surface, whereas in conductors, the electrons would simply flow away.