Answer:
- Newton's first law applies. An object at rest will stay that way until a force is applied.
- Any amount of effort can be applied to any amount of mass (in the ideal case). The question is not sufficiently specific.
Explanation:
A force is required to move an object because the object will stay at rest until a force is applied.
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The effort required to lift or push two masses instead of one depends on the desired effect. For the same kinetic energy, no more effort is required. For the same momentum, half the effort is required for two masses. For the same velocity, double the effort is required.
Answer:
a) 5 N b) 225 N c) 5 N
Explanation:
a) Per Coulomb's Law the repulsive force between 2 equal sign charges, is directly proportional to the product of the charges, and inversely proportional to the square of the distance between them, acting along the line that joins the charges, as follows:
F₁₂ = K Q₁ Q₂ / r₁₂²
So, if we make Q1 = Q1/5, the net effect will be to reduce the force in the same factor, i.e. F₁₂ = 25 N / 5 = 5 N
b) If we reduce the distance, from r, to r/3, as the factor is squared, the net effect will be to increase the force in a factor equal to 3² = 9.
So, we will have F₁₂ = 9. 25 N = 225 N
c) If we make Q2 = 5Q2, the force would be increased 5 times, but if at the same , we increase the distance 5 times, as the factor is squared, the net factor will be 5/25 = 1/5, so we will have:
F₁₂ = 25 N .1/5 = 5 N
Convection occurs because the oceanic waters heat up becoming less dense. This water moves above the cooler water, and give off its heat to the surrounding environment. As it cools, it begins to sink, and the process begins again.
Answer:
The horizontal component of the velocity vector is;
vh = 34.4 ft/s
The vertical component of the velocity vector is;
vy = 49.1 ft/s
Explanation:
Given;
Velocity of football v = 60 ft/s
Angle of elevation ∅ = 55°
The horizontal component of the velocity vector is;
vh = vcos∅
Substituting the values;
vh = 60cos55°
vh = 34.41458618106 ft/s
vh = 34.4 ft/s
The vertical component of the velocity vector is;
vy = vsin∅
Substituting the values;
vy = 60sin55°
vy = 49.14912265733 ft/s
vy = 49.1 ft/s
Answer:
65.9°
Explanation:
When light goes through air to glass
angle of incidence, i = 35°
refractive index, n = 1.5
Let r be the angle of refraction
Use Snell's law
Sin r = 0.382
r = 22.5°
Now the ray is incident on the glass surface.
A = r + r'
Where, r' be the angle of incidence at other surface
r' = 60° - 22.5° = 37.5°
Now use Snell's law at other surface
Where, i' be the angle at which the light exit from other surface.
Sin i' = 0.913
i' = 65.9°
