Draw a digital signal
The box is being pushed to the right with a force of 300 newtons, and to the left with a force of 400 newtons.
Which is the net force on the box?
100 N
What happens when two negatively charged particles are next to each other?
The particles repel each other
When two objects have different electric charges they __________.
pull toward each other
VCR's (Video Tape Recorders) are examples of
analog technology
Digital technology
True or False
A swimmer swims across a swimming pool, and at the end the pool she turns around and pushes off the wall with her feet. The action-reaction forces would be the force of her feet on the wall and the force of the wall on her feet.
True
The figure below shows the top view of a bar magnet sitting at rest on a table top.
If a compass is placed in the position indicated by the dotted circle, in which direction will the compass needle point? Note: The black portion of the compass needle is a magnetic north pole.
he figure below shows the top view of two bar magnets sitting at rest on a table top. The direction of Earth’s geographic North Pole is given in the figure.
If a compass is placed directly between the magnets, in which direction will the compass point? Note: The black portion of the compass needle is a magnetic north pole.
Two forces act in opposite directions on a wood block. What will happen if the forces are unbalanced?
The position of the block will change.
True or False
Digital signals are a perfect copy of the original
False
A student pushes on an object with a force of 6 newtons and the object does not move. What force does the object exert on the student’s hands?
6 Newtons
Why do planets stay in orbit around the Sun?
attraction of gravity
Magnet 2 has a stronger magnetic field than Magnet 1.
Remote controllers use what type of electromagnetic waves
Infrared Radiation
Why are optical fibers used for communication?
Optical fibers can send a lot of information
A force of 20 N acts upon a 5 kg block. Calculate the acceleration of the object.
4 m/s2
Tides on Earth are influenced more by the Moon than the Sun because the Moon is
closer than the Sun
The magnitude of the gravitational force between two planets depends on the
distance between the planets.
True or False
This represents the velocity of a moving object:
40 m/s north
True
State all the types of electromagnetic waves that can be used for communication.
Radio waves
Microwaves
IR
Visible light
Student 1 rides in a moving car and observes a bus traveling east. She estimates that it is traveling at a rate of 20 kilometers per hour (km/h). Student 2 is standing on the sidewalk and observes the same bus at the same time. She estimates that it is moving east at a rate of 50 km/h.
Explain the difference.
All motion is relative to the frame of reference chosen for measurement.
The gravity of the Sun is 179 times that of the gravity of the Moon. What is the main reason that the Moon has a stronger gravitational effect on Earth’s oceans and tides than does the Sun?
Distance plays a greater role in gravitational force than mass.
Amanda weighs about 600 N on Earth, but would only weigh about 100 N on the Moon. Explain why Amanda would weigh less on the Moon than on Earth?
The mass of the Moon is less than that of Earth, therefore it has a weaker gravitational force.