Answer:
B
Explanation:
Given that an elevator moving down passes its neighbor, an elevator moving up. Their speed relative to one another is 8 m/s. What is the velocity of each elevator relative to someone standing on the first floor? Assume that the elevators are traveling at the same speed, and that the upward direction is
positive.
Solution
Given that upward direction is positive, then, the downward direction will be negative.
To get a relative velocity of 8m/s
4 - ( - 4 ) = 8
Therefore, the correct answer will be
One elevator is moving at 4 m/s; the other elevator is moving at -4 m/s
Which is option B
Because the negative multiply by negative sign will give positive sign.
Given
4 + 4 = 8.
Answer:
carbon, hydrogen, nitrogen and oxygen
Cations are positively charged ions. And for positive charged ions, it means the positive charges, protons, are more than the negative charges, the electrons.
Therefore Cations have fewer electrons than protons.
So the answer is: c. electrons; protons.
Answer:
12.56 A.
Explanation:
The magnetic field of a conductor carrying current is give as
H = I/2πr ............................... Equation 1
Where H = Magnetic Field, I = current, r = distance, and π = pie
Making I the subject of the equation,
I = 2πrH............... Equation 2
Given: H = 1 T, r = 2 m.
Constant: π = 3.14
Substitute into equation 2
I = 2×3.14×2×1
I = 12.56 A.
Hence, the magnetic field = 12.56 A.
Answer:
a)
b) parallel to the earth surface.
- In this case according to the Fleming's left hand rule the direction of movement of bee must be in a direction parallel to the earth surface and perpendicular to the electric field at the same time.
Explanation:
Given:
mass of the bee,
charge acquired by the bee,
a.
Electrical field near the earth surface,
Now the electric force on the bee:
we know:
The weight of the bee:
Therefore the ratio :
b.
The condition for the bee to hang is its weight must get balanced by the electric force acing equally in the opposite direction.
So,
parallel to the earth surface.
- In this case according to the Fleming's left hand rule the direction of movement of bee must be in a direction parallel to the earth surface and perpendicular to the electric field at the same time.