4) B) Speed = Distance/ time
5) C) By applying second law of newton " F = ma" we say that "15 = 12 × acceleration"
15/12= acceleration
acceleration = 1.25 m/s2
6) D) It will continue to accelerate to the right but at a slower rate because of the small force (F2) being applied from the right.
To determine the answer to this item, we use two (2) equations.
Equation for kinetic energy:
KE = 0.5 mv²
Equation for momentum:
P = mv
From the second equation, we can deduced that,
m = P/v
Substituting the known values from the given above,
m = 30/v
Using this expression in the first equation,
KE = 0.5 mv²; 150 = 0.5(30/v)(v²)
The value of v from the equation is 10 m/s.
The mass is therefore calculated as such,
m = 30/v = 30/10 = 3 kg
Hence, the answers are,
<em> Mass = 3 kg</em>
<em> Velocity = 10 m/s</em>
Answer:
A semiconductor acts like an ideal insulator at absolute zero temperature that is at zero kelvin. It is because the free electrons in the valence band of semiconductors will not carry enough thermal energy to overcome the forbidden energy gap at absolute zero.
It is very difficult for an atom to accept a proton. It can only be done under very special circumstances. So A and C are both incorrect. I don't see how D is possible. The atom does lose 1 electron, but how it gets 21 is think air.
The answer is B which is exactly what happens.
