Answer:
The sum of positive and negative charges in a unit of Al2O3 equals zero.
Aluminium has a charge of +3 while Oxygen has a charge of -2 on each ion.
Al203 has 2 Al atoms and 3 O atoms.
Charge on Al2O3 = 2(charge on Al ion) + 3(charge on O ion)
= 2(3) + 3(-2)
= 6 - 6
= 0
Explanation:
Aluminium has 3 electrons in the outermost shell and has the tendency to lose those 3 electrons to form a positive ion and have a complete outermost shell.
Whereas, Oxygen has 6 electrons in the outermost and has the tendency to accept two more electrons to form a negative ion and have a complete outermost shell.
Answer:
The ball has no momentum
Explanation:
The given parameters are;
The mass of the ball = 5 kg
The velocity of the ball = 0 (The ball is sitting on the floor without moving)
The momentum of the ball = The mass of the ball × Velocity of the ball
Therefore, the momentum of the ball = 5 kg × 0 m/s = 0
The momentum of the ball is zero, the ball has no momentum.
Answer:
50 W
Explanation:
<h3>
<u>Given :</u></h3>
- Force applied = 100 N
- Distance covered = 5 metres
- Time = 10 seconds
<h3>
<u>To find :</u></h3>
Power
<h3>
<u>Solution :</u></h3>
For calculating power, we first need to know about the work done.
Now, substituting values in the above formula;
Work = 100 × 5
= 500 Nm or 500 J
We know that,
Substituting values in above formula;
Power = 500/ 10
= 50 Nm/s or 50 W
Hence, power = 50 W .
The statement that is true of cooling down after physical activity is that you should cool down for about 5 to 10 minutes after being physically active.
<h2>
Option 1 is the correct answer.</h2>
Explanation:
Power of heater, P = 1790 W
Time used, t = 24 hours = 24 x 60 x 60 = 24 x 3600 s
We have the equation
We need to find energy,
Substituting
Energy = 1790 x 24 x 3600 J
Option 1 is the correct answer.
