This is a physical change because there isn’t a change in composition of the substance, sand. It is only changing the shape, not having a chemical reaction of any sort.
I hope this helps!
The wording of the choices is really unclear. With two resistors in parallel,
here's the situation:
-- The voltage across each resistor is the same as the voltage across
the other one. If the parallel combination is connected to the battery,
then the voltage across each resistor is the full battery voltage.
-- The current through each resistor is (V) / (the resistance of that resistor).
That's the same current as would flow through that resistor if the other one
were not there.
-- As long as the battery or other power supply holds out, neither of these
quantities changes.
Can you match this situation to one of the choices listed ?
It looks to me as if choice 'C' is the one that's most likely
trying to say this.
Answer:
The puck B remains at the point of collision.
Explanation:
This is an elastic collision, so both momentum and energy are conserved.
The mass of both pucks is m.
The velocity of puck B before the collision is vb.
The velocity of puck A and B after the collision is va' and vb', respectively.
Momentum before = momentum after
m vb = m vb' + m va'
vb = vb' + va'
Energy before = energy after
½ m vb² = ½ m vb'² + ½ m va'²
vb² = vb'² + va'²
Substituting:
(vb' + va')² = vb'² + va'²
vb'² + 2 va' vb' + va'² = vb'² + va'²
2 va' vb' = 0
va' vb' = 0
We know that va' isn't 0, so:
vb' = 0
The puck B remains at the point of collision.
Answer:
the energy absorbed is 4.477 x 10⁶ J
Explanation:
mass of the liquid, m = 13 kg
initial temperature of the liquid, t₁ = 18 ⁰C
final temperature of the liquid, t₂ = 100 ⁰C
specific heat capacity of water, c = 4,200 J/kg⁰C
The energy absorbed is calculated as;
H = mcΔt
H = mc(t₂ - t₁)
H = 13 x 4,200(100 - 18)
H = 4.477 x 10⁶ J
Therefore, the energy absorbed is 4.477 x 10⁶ J
Answer:
Proton, neutron, electron
Explanation:
The atom consists of a nucleus, where almost all the mass is concentrated, and electrons orbiting around the nucleus.
The nucleus consists of two types of particles:
- Proton: it has a mass of 
, and a positive electric charge of +e (
)
- Neutron: it has a mass of 
, and it has no electric charge
The third particle that makes an atom is the electron, that orbit around the nucleus:
- Electron: it has a mass of 
, and it has a negative electric charge of -e (
)
