The official web site of the Nobel Prize explains that Marie Curie’s chemistry prize was partly for her discovery that the radioactivity of a substance is unaffected when it undergoes a chemical reaction. The discovery implied was that, Radioactivity involves Radioactivity involves only neutrons.
Explanation:
- The official web site of the Nobel Prize explains that Marie Curie’s chemistry prize was partly for her discovery that the radioactivity of a substance is unaffected when it undergoes a chemical reaction. The discovery implied was that, Radioactivity involves only neutrons.
- Marie Curie studied about the radiation of all compounds containing the known radioactive elements, including uranium and thorium, which she later discovered that they were radioactive.
- she discovered the following results,
- the exact measurement of the strength of the radiation from uranium;
- the intensity of the radiation was found to be proportional to the amount of uranium or thorium in the compound .
- the ability to emit radiation is not dependent on the arrangement of the atoms in a molecule;
- it must be linked to the interior of the atom itself which is a revolutionary discovery.
Answer:
SECOND LAW OF NEWTON
Explanation:
When the rocket fires the engines the gases leave at high speed and collide with the space station, transferring an impulse given by the expression
I = F t = Δp
As we can see this expression is a form of Newton's second law
F = m a
a = dv / dt
F = m dv / dt
F dt = m dv
p = mv
F dt = dp
Therefore the station moves through the SECOND LAW OF NEWTON
Answer:
Explanation:
Recall the formula for acceleration:
, where 
is final velocity, 
is initial velocity, and 
is elapsed time (change in velocity over this amount of time).
Let's look at our time vs velocity graph. At t=0 seconds, V=25 m/s. So her initial velocity is 25 m/s.
We want to find the acceleration during the first 5 seconds of motion. Well, looking at our graph, at t=5 seconds, isn't our velocity still 25 m/s? Therefore, final velocity is 25 m/s (for this period of 5 seconds).
We are only looking from t=0 seconds to t=5 seconds which is a total period of 5 seconds. Therefore, elapsed time is 5 seconds.
Substituting values in our formula, we have:
Alternative:
Without even worrying about plugging in numbers, let's think about what acceleration actually is! Acceleration is the change in velocity over a certain period of time. If we are not changing our velocity at all, we aren't accelerating! In the graph, we can see that we have a straight line from t=0 seconds to t=5 seconds, the interval we are worried about. This indicates that our velocity is staying the same! At t=0 seconds, we have a velocity of 25 m/s and that velocity stays the same until t=5 seconds. Even though we are moving, we haven't changed velocity, which means our average acceleration is zero!
Answer:
2. How many joules of heat are needed to raise the temperature of 10.0 g of aluminum from 22°C to 55°C, if the specific heat of aluminum is 0.90 J/gºC? c=0.90J/g. 9 (2 sigs.)
Explanation:
D. March because it is just below the 1 million marker on the graph and it is the only one that low.
