Answer:
A). A Lever and Wheel and Axle.
Explanation:
1. A wheel axle is most obvious, as the wheels are connected via a chain and axle with spokes. This helps keep the wheels moving forward with less effort than walking.
2. A Lever is used to help Balance you as you ride the bike. Without it, you would tip over, and lose all the momentum you had gained up until that point.
3. (I took the test on e2020)
Answer:
Transverse wave- Back and forth at right angles to the direction of the wave arrow.
longitudinal wave- bask and forth in the direction of the motion of the motion of the wave.
electromagnetic wave- two alternating waves moving at right angles to each other.
Explanation:
In a longitudinal wave, the particles vibrate at right angles in reference to the wave motion.
In a transverse wave, the particles vibrate parallel to the wave motion
Electromagnetic waves occur as a result of the interaction between two waves and are normally transverse in nature.
The reason is that a closed system has nothing going in or out and water retains energy very well also water it polar so it is attracted to itself. It doesnt like contact with other things.
So it's likely to be C
Answer:
mass- the amount of matter in an object
balance- tool used to measure mass
scale- a tool used to measure weight
weight- the downward pull on an object due to gravity
Answer: (2) Use the Momentum Principle.
Explanation:
In fact, it is called the <u>Conservation of linear momentum principle,</u> which establishes the initial momentum 
of the asteroids before the collision must be equal to the final momentum 
after the collision, no matter if the collision was elastic or inelastic (in which the kinetic energy is not conserved).
In this sense, the linear momentum 
of a body is defined as:
Where 
is the mass and 
the velocity.
Therefore, the useful approach in this situation is<u> option (2)</u>.
