Science

Why simple machines are useful in our everyday living?

• they reduce effort and extend extend the ability of people to perform tasks beyond their strength or ability

• they make them stronger

• it change the amount of energy

• it decrease the amount of work

Which of the following best describes sound?

• Sound energy things produce when objects vibrate

• sound energy is present in everybody

• it produced when sound waves move inward to a vibrating object or sound source

• sound is the term to describe what is seen when sound waves pass through a medium to the source

What simple machine is made of an inclined plane wrapped around a cylinder?

• lever

• wedge

• screw

• inclined plane

Which forms of energy travels in a form of electromagnetic (ED waves?

• A. heat energy

• B. light energy

• C. chemical energy

• D. mechanical energy

What is the advantage of using LED (light emitting diode) lighting?

• LEDs are less effective in wide area.

• LEDs are more expensive than other lights.

• LEDs has a long life compared to other lights.

• LEDs can get damaged due to high voltage sometimes.

Which of the following is a way of conserving of energy?

• Iron clothes every day.

• Use a washing machine overload.

• When the food boils, set your stove to high.

• Turn off lights and other appliances when not in use.

In a playground, there's a boy and girl on a see saw. The boy may not be able to lift the girl up in the air using just his arms. On a see saw, though, the girl is sitting on one end and then the boy can easily push down on the other end and lift the girl. This is exactly how a see saw works and it is an example of lever. How are levers classified?

• force applied to the effort arm

• direction of force and efficiency

• mechanical advantage of the tool

• position of effort, resistance, and fulcrum

It is an inclined plane or two inclined planes that meet each other to form a sharp edge. It is usually good for cutting and piercing

• lever

• screw

• wedge

• pulley

Which of the following statements best describes a block-and-tackle pulley?

• It is made up of a small wheel that turns into axle.

• It is made of grooved wheel that turns about a stationary axle in which a rope moves.

• It is made up of two pulleys, one fixed and another pulley which moves with the load.

• It is made of a compound pulley, made of a combination of fixed and movable pulley.

Which of the following forms of energy travels in a form of electromagnetic (ED waves?

• heat energy

• light energy

• chemical energy

• mechanical energy