Il existe troi types de rayons produits lors de la désintégration des éléments radioactifs:
-- "particules alpha" . . . noyaux d'hélium, composés chacun de 2 protons et 2 neutrons
-- "rayons bêta" ou "particules bêta" . . . flux d'électrons
-- "rayons gamma" . . . rayonnement électromagnétique avec les longueurs d'onde les plus courtes connues et l'énergie la plus élevée
Answer:
1. 150C.
2. 50sec
3.1.5a
Explanation:
1. I = Q/T
Q= 30x5
=150c
2.applying the formulae, I = Q/T
T= Q/I
=500/10
=50sec.
3. using the formulae i=q/t
i= 120/80
=1.5a.
Answer:
The central blue square in between the lower pair of magnet has the least force of repulsion.
Explanation:
We can explain this using the dual nature of magnets.
Each magnet must have two poles namely:
-North pole
-South pole
We assume that the magnetic lines of forces enters from south pole and leaves from the north pole.
When brought together, like poles repel each other while opposite poles attract each other.
In the picture, the lower two magnets have opposite poles facing each other, hence the force of repulsion is minimum there and the force of attraction is maximum.
All that business about the crane and the rope and the falling
is only there to confuse us.
The piano ended up 5 meters above the ground.
Potential energy = (mass) (gravity) (height)
= (200 kg) (9.81 m/s²) (5 m)
= (200 · 9.81 · 5) (kg-m²/s²)
= 9,810 joules .
