1) C. velocity
Acceleration is defined as the rate of change of velocity per unit time. In formulas:

where
is the change in velocity
is the time interval
Therefore, the correct answer is C. velocity.
2) A. 9.8m/s/s
Earth's gravity is a force, so it produces an acceleration on every object with mass located on the Earth's surface. This acceleration can be calculated, as it is given by the formula

where
is the gravitational constant
is the Earth's mass
is the Earth's radius
By substituting these numbers into the formula, one can find that the acceleration due to Earth's gravity is
.
Answer:
We can retain the original diffraction pattern if we change the slit width to d) 2d.
Explanation:
The diffraction pattern of a single slit has a bright central maximum and dimmer maxima on either side. We will retain the original diffraction pattern on a screen if the relative spacing of the minimum or maximum of intensity remains the same when changing the wavelength and the slit width simultaneously.
Using the following parameters: <em>y</em> for the distance from the center of the bright maximum to a place of minimum intensity, <em>m</em> for the order of the minimum, <em>λ </em>for the wavelength, <em>D </em>for the distance from the slit to the screen where we see the pattern and <em>d </em>for the slit width. The distance from the center to a minimum of intensity can be calculated with:

From the above expression we see that if we replace the blue light of wavelength λ by red light of wavelength 2λ in order to retain the original diffraction pattern we need to change the slit width to 2d:
<em> </em>
The answer is "B".. Galileo discovered that dropping two items of the same mass, they can have different weights but no matter what the force that is acting upon them is the same amount, so this means that both objects will hit the ground at the same time. Galileo tested this theory and proved it right.
<span>The observation or measurement of physical properties of matter does not change its composition or its chemical nature. Other examples of physical properties include the infrared spectrum, attraction or repulsion to magnets, viscosity and opacity.</span>
Answer:
The answer to your question is 2.1 g/ml
Explanation:
Data
volume = 30 ml
mass = 63 g
density = ?
Process
Density is defined as the mass per unit volume. The units of density are g/ml or kg/m³.
Formula
Density = mass / volume
Substitution
Density = 63 / 30
Result
Density = 2.1 g/ml