Copy of 7th Grade Semester 2 Final

What happens if you break a magnet in half?

• One half will have a north pole only and one half will have south pole only
• Neither half will have a pole
• Each half will be a new magnet, with both a north pole and a south pole
• Neither half will be able to attract or repel

Magnetic field lines around a bar magnet.......

• are perpendicular to the magnet
• spread out from the poles and curve around the magnet
• cross back and forth over one another
• are perfectly straight

The amplitude of the wave is .....

• the distance between the crest and the trough of the wave
• the distance from the crest to rest or the trough to the rest
• the distance the wave moves in one second
• the distance the wave moves in one time period of the wave

If a sound is low pitched and loud, the sound wave is....

• low frequency and high amplitude
• high frequency and low amplitude
• high frequency and high amplitude
• low frequency and low amplitude

Calculate the net force and the direction the object will move. You push on a crate with a force of 10N to the right, and your friend pushes on the crate with a force of 25N to the left. What is the net force and the direction the crate will move. (need both)

• 15N Right
• 15N Left
• 35 N Right
• 35 N Left

Matt has a mass of 60Kg. He pulls on a wagon with a mass of 30 kg with a force of 20N. The wagon remains unmoved. The wagon exerts a force of _______N on Matt.

• 0 N
• 10N
• 20N

Newton's first law of motion states that an object stays in constant motion unless a(n) ________________ force acts on it.

• balanced
• unbalanced
• acceleration

According to Newton's second law of motion __________.

• F = mv (force = motion times velocity)
• F = m/a (force = motion divided by acceleration)
• F = ma (force = motion times acceleration)

The statement "for every action, there is an equal but opposite reaction" is a statement of _______.

• Newton's First Law
• Newton's Second Law
• Newton's Third Law

Every magnet regardless of its shape, has two ______.

• magnetic poles
• magnetic charges
• magnetic fields