What are we suppose to do to help?
Answer:
a) true.
b) True
c) False. In the equation above the mass does not appear
d) True
e) False. Mass does not appear in the equation
f) False. The load even when distributed in the space can be considered concentrated in the center
Explanation:
1. The electric force is given by the relation
F = k Q e / r2
where k is the Coulomb constant, Q the charge used, e the charge of the electron and r the distance between the two.
The strength depends on:
a) true.
b) True
c) False. In the equation above the mass does not appear
d) True
e) False. Mass does not appear in the equation
f) False. The load even when distributed in the space can be considered concentrated in the center
two.
a) True
b) Treu
c) Fail
f) false
Answer:
π/2 (90°)
Explanation:
The dot product of two vectors equals the product of their magnitudes and the cosine of the angle between them.
a·b = ||a|| ||b|| cos θ
If the dot product is 0:
0 = ||a|| ||b|| cos θ
0 = cos θ
θ = π/2
The angle between a and b is π/2 (90°).
Answer:1.) 2 seconds
2.) 4.5 hertz
3.) it will become one third is original value
4.)5.9 seconds
5.)0.87 meters
Explanation:
In 1 hour, the hour hand sweeps across 1/12 of the clock's face. In 40 min, the hour hand travels (40 min)/(60 min) = 2/3 of the path it covers in an hour, so a total of 1/12 × 2/3 = 1/18 of the clock's face. This hand traces out a circle with radius 0.25 m, so in 40 min its tip traces out 1/18 of this circle's radius, or
1/18 × 2<em>π</em> (0.25 m) ≈ 0.087 m
The minute hand traverses (40 min)/(60 min) = 2/3 of the clock's face, so it traces out 2/3 of the circumference of a circle with radius 0.31 m:
2/3 × 2<em>π</em> (0.31 m) ≈ 1.3 m
The second hand completes 1 revolution each minute, so in 40 min it would fully trace the circumference of a circle with radius 0.34 m a total of 40 times, so it covers a distance of
40 × 2<em>π</em> (0.34 m) ≈ 85 m
