Answer:
The cathode ray is deflected vertically to the fluorescent screen
Explanation:

Answer:
As the sound approaches, it gets louder (simply because you're closer to the source), and has a higher pitch. Then, as it passes, the sound suddenly dips down, and as it drives away you hear a lower pitch, plus a decreasing volume as the engine gets farther and farther away.
Explanation:
The correct answer is:

Let's see why.
1 amu corresponds to the mass of the proton, which is:

if we convert this into energy, using Einstein equivalence between mass and energy, we find:

Now we can convert it into electronvolts:

So, 1 amu = 934 MeV. Therefore, 3 amu corresponds to 3 times this value:
Answer
Radius of the wheel r = 2.1 m
Moment of inertia I = 2500 Kg m²
Tangential force applied F = 18 N
Time interval t = 16 s
Initial angular speed ω1 = 0
Final angular speed ω2 = ?
Let α be the angular acceleration.
Torque applied τ = Iα
F r = Iα
Angular acceleration α = F r/I
= 
= 0.015 rad/s²
(a)From rotational kinematic relation
Final angular speed ω₂ = ω₁ + αt
= 0 + (0.015 rad/s^2 * 16 s)
= 0.24 rad/s
(b) Work done W = 0.5 Iω₂² - (1/2)Iω₁²
= 0.5*( 2500 Kg m²)(0.24 rad/s)^2 - 0
= 72 J
(c) Average power supplied by the child P = W/t = 
= 4.5 watt
If you give it unbalanced force it would go up and if you can't give it enough it will stay a balanced force