Explanation

• The electricity used in homes and schools is typically Alternating Current (AC).
• It is the type of electric current that periodically changes direction.
• This is the type of current provided by power plants and distributed through the grid.

Explanation

• Car brakes are typically hydraulic systems, not pneumatic systems.

The examples of pneumatic systems:

• Spray gun: uses compressed air to atomize and spray paint or other materials.
• Bicycle pump: uses compressed air to inflate tires.
• Vacuum cleaner: uses compressed air to create suction and lift dust and debris.

Explanation

Sound waves in air are longitudinal waves

Because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves.

Explanation

• The Earth is part of the Milky Way Galaxy.
• It is a barred spiral galaxy containing hundreds of billions of stars, gas, and dust.

Explanation

• Vesta is the largest asteroid in the asteroid belt between Mars and Jupiter.
• It is believed to have a buried ocean 30 miles deep.
• It is thought to have a thin ocean with high salt concentrations.
• Vesta's surface is icy and rocky, with many craters and canyons.

Explanation

• When the Moon and the Sun are on opposite sides of the Earth, we see a Full Moon.
• This occurs when the entire face of the Moon is illuminated by the Sun, making it visible all night long.

Explanation

• When a magnet is suspended freely, its north pole will point towards the Earth's magnetic South pole (which is located near the Earth's geographic North pole), and its south pole will point towards the Earth's magnetic North pole (which is located near the Earth's geographic South pole).
• This is because opposite poles attract, and the Earth's magnetic field is strong enough to align the magnet's poles.

Explanation

A screw is a simple machine that is an inclined plane wrapped around a cylinder. 

It is used to fasten objects together, and it is used in:

• Fastening parts together
• Holding things in place
• Providing a secure grip

Examples include:

• Wood screws (used in woodworking and construction)
• Machine screws (used in machinery and equipment)
• Self-tapping screws (used in plastic and metal)
• Bolts (used in heavy-duty applications)
• Lag screws (used in heavy construction)
• Deck screws (used in decking and outdoor construction)
• Drywall screws (used in drywall installation)
• Anchor screws (used in concrete and masonry)

Explanation

The minute hand of a clock moves 360 degrees (or 2π radians) in 60 minutes, which is equivalent to 1 hour.

To find the angular velocity, we can use the formula:

ω = Δθ / Δt

where ω is the angular velocity, Δθ is the change in angle (2π radians), and Δt is the time (1 hour or 3600 seconds).

Plugging in the values, we get:

ω = 2π radians / 3600 s ≈ 0.00175 rad s⁻¹

So, the angular velocity of the minute hand is approximately 0.00175 rad s⁻¹.

Explanation

• The relationship between current and potential difference (voltage) across a resistor is governed by Ohm's Law, which states that: I = V/R
• where I is the current, V is the voltage, and R is the resistance.
• This relationship is linear, meaning that if the voltage is reversed (i.e., the connections across the resistor are reversed), the current will also be reversed, but the graph will still be a straight line.