Answer:
d) The speed of the astronaut
Explanation:
The sentence describes the speed of the astronaut. This speed value is 10meters per minute.
Now let us understand why;
- Speed is the distance divided by time. It is a scalar quantity without regard for direction but it has magnitude.
- The value 10meters per minute clearly shows this instance. We do not know the direction the astronaut is moving towards.
- Velocity, like speed is the displacement of a body with time. It is a vector quantity and it shows the direction of motion.
- For example, 10m/s due west is a velocity value because we know the direction.
Therefore, since there is no directional sense, the value indicates speed.
Sound intensity = 1/(r^2)
That is Sound intensity is indirectly proportional to the distance. Therefore, sound becomes 9 times less intense.
Answer:
Work done.
Explanation:
The skater who lifts has to overcome the partner's weight. When lifted up by 1 meter, her potential energy increases by (mass)x(gravitational acceleration)x(1meter), which is the amount of work done.
(This all assumes lifting vertically and no other forces being part of the picture)
Answer:
O²⁻
Explanation:
Number of protons = 8
Number of neutrons = 9
Number of electrons = 10
What type of atom or ion is it = ?
Solution:
Protons are the positively charged particle in an atom
Neutrons do not carry any charges
Electrons are negatively charged particles
For this atom, the number of protons helps to identify what specie it is; so this is an oxygen atom.
Now,
Charge = Number of protons - Number of electrons
Charge = 8 - 10 = -2
The charge on the atom is -2 and so it is an oxygen ion with -2 charge
The ion is O²⁻
