Conceptual
Why does rubbing a balloon on your hair make your hair stick up?
Electrons transfer from your hair to the balloon, leaving your hair positively charges and it repels itself.
Two charges are originally 2 cm apart. If they are moved to 6 cm apart, how does the force between them change?
It is 9 times weaker (1/9 the force)
625 N
Name three ways to increase an objects GPE.
more mass, more gravity, more height
Carbon 14 (6 protons) undergoes beta-minus decay. What particle is emitted and what is the remaining nucleus?
An electron is emitted and the new nucleus is Nitrogen (7 protons)
All fields have what 4 things?
Direction, Source, Magnitude, Potential
Two charges experience a 100 N force. What are two ways to increase that force to 400N?
Increase one of the charges x4, increase both charges x2, or halve the distance.
What are two ways to decrease the force of gravity between two objects?
Decrease the mass, increase distance
Explain insulators vs conductors with examples of each.
Insulator: doesn't move charges (glass, plastic, wood)
Conductor: easily moves charges (metals)
Carbon 10 (6 protons) undergoes beta-plus decay. What particle is emitted and what is the remaining nucleus?
A positron is emitted and Boron is the new nucleus (5 protons)
Two negative charges move away from each other. Describe their energy transformations.
Their EPE is decreasing as it is converted into KE
Charge A experiences a force from Charge B of 1200 N. How much force does charge B experience?
1200 N
The inverse square law means...
As one value (distance) increases, another value (force) decreases rapidly, then levels out while never reaching zero
A cup of ice water is left outside on a summer day. Explain what will happen to its thermal energy.
Its thermal energy will increase as energy from the air enters the water. This will cause the ice to melt as that thermal energy enters the ice.
Uranium (92 protons) undergoes alpha decay. What particle is emitted and what is the new nucleus?
An alpha particle is emitted (helium nucleus) and the new nucleus is Thorium (90 protons)
Closest to the first charge.
80 N
What happens to an object's gravitational potential energy as it moves away from the source of gravity?
GPE increases as distance increases.
A skydiver is rapidly losing potential energy. What is happening to their energy and why?
It is being converted to KE as gravity pulls them to the center of the earth.
Thorium undergoes gamma decay. What particle is emitted and what is the new nucleus?
A photon (gamma ray) is emitted, and the nucleus remains Thorium
How does a Van de Graaf generator work?
Metal brushes scrape along a rubber belt, transferring electrons to the belt. The rubber belt then carries the electrons to a metal dome.
Charge A and Charge B are within each other's electric fields. Charge A carries 3x the charge of Charge B. How much more force does it experience?
They experience the same amount of force.
Jupiter is much farther from the Sun than Earth. Why would we experience a greater force of gravity on Jupiter than here?
On Jupiter's surface, the main source of gravity is Jupiter itself, which has a much larger mass than Earth.
How does an airbag help protect you in a car accident?
It increases the time it takes for your body to come to a complete stop (momentum 0), which decreases the force.
(Impulse)
Explain nuclear fusion vs fission
Fusion = 2 nuclei combine together