The options are;
A) The skater experiences acceleration both while skating in a straight line and while making her turn.
B) Because the skater does not change her direction or speed, she does not experience acceleration.
C) The skater only experiences acceleration when she is turning.
D) The skater only experiences acceleration while skating in a straight line.
Answer:
A: The skater experiences acceleration both while skating in a straight line and while making her turn
Explanation:
We are told that She speeds up on the straight portion of the rink. This means that she experienced an acceleration since the speed was not constant but gradually increasing.
Also, we are told that She slows down near each end of the rink and then turns around. This means that she reduced speed before turning and it means there was also an acceleration as well when making the turn.
Thus, she experience acceleration both in the straight line and when making turn.
Option A is correct
Answer:
An Orbital is best described as the volume of space in which electrons are most often found
Explanation:
As we know atom consists of sub-particles commonly known as protons, neutrons and electrons. The outer space around the nucleus where the probability of finding electrons is maximum is known as orbital. As the electrons are not precisely ordered around the nucleus hence it is not easy to tell the exact position of an electron.
Hence, four quantum numbers are used to locate the position of electrons around the nucleus.
i) Principle Quantum Number:
This number explains the main energy level which tend to increase in energy as the distance of electrons from nucleus are increased. Principle Quantum Numbers are integer number ranging from one to infinity. Hence, increase in this quantum number results in increase of the size of orbital.
ii) Azimuthal Quantum Number:
This Quantum Number explains the direction of particular orbital in 3-dimensional space. Also it is responsible for the shape of an orbital.
iii) Magnetic Quantum Number:
This Quantum Number also tells the direction of orbital in 3D space with respect to x, y and z axis.
iv) Spin Quantum Number:
This Quantum Number tells about the spin direction of an electron about its axis which may be clockwise or anticlockwise.
Answer:
a. The reaction is endothermic.
Explanation:
The heat involved in a chemical reaction is given by the enthalpy change (ΔH), which is equal to the balance between the chemical bonds that are broken (release energy) and the chemical bonds that are formed (need energy):
ΔH ≅ bonds broken - bonds formed
If broken bonds > bonds formed ⇒ ΔH > 0 ⇒ endothermic reaction
Therefore, the reaction is endothermic (it requires energy).
Answer:
velocity = 29925×10⁶ m/s
Explanation:
Given data:
Frequency = 35 MHz
Wavelength = 855 m
Velocity = ?
Solution:
MHz to Hz
35×10⁶ Hz
Formula:
<em>velocity = Wavelength × Frequency</em>
velocity = 855 m × 35×10⁶ Hz
velocity = 29925×10⁶ m/s
Hz = s⁻¹
