Answer:
Explanation:
1. radio waves from am
2. radio waves from fm
3.yellow light from a sodium street lamp
4. microwaves from an antenna of a communications system.
Answer:
E = 9.4 10⁶ N / C, The field goes from the inner cylinder to the outside
Explanation:
The best way to work this problem is with Gauss's law
Ф = E. dA = qint / ε₀
We must define a Gaussian surface, which takes advantage of the symmetry of the problem. We select a cylinder with the faces perpendicular to the coaxial.
The flow on the faces is zero, since the field goes in the radial direction of the cylinders.
The area of the cylinder is the length of the circle along the length of the cable
dA = 2π dr L
A = 2π r L
They indicate that the distance at which we must calculate the field is
r = 5 R₁
r = 5 1.3
r = 6.5 mm
The radius of the outer shell is
r₂ = 10 R₁
r₂ = 10 1.3
r₂ = 13 mm
r₂ > r
When comparing these two values we see that the field must be calculated between the two housings.
Gauss's law states that the charge is on the outside of the Gaussian surface does not contribute to the field, the charged on the inside of the surface is
λ = q / L
Qint = λ L
Let's replace
E 2π r L = λ L /ε₀
E = 1 / 2piε₀ λ / r
Let's calculate
E = 1 / 2pi 8.85 10⁻¹² 3.4 10-12 / 6.5 10-3
E = 9.4 10⁶ N / C
The field goes from the inner cylinder to the outside
Answer:
789.8 W
Explanation:
mass of the cab = 1400 kg, the counter weight of the elevator = 930 kg
weight of the cab = 1400 × 9.81 where weight = mg and m is mass and g is acceleration due to gravity.
weight of the cab = 13734 N
counter weight of the elevator = 930 × 9.81 = 9123.3 N
the exerted force of the elevator = weight of the cab - counter weight of the elevator = 13734 - 9123.3 = 4610.7 N
Average power by the motor P = F × v = F × distance / time
where v is speed in m/s, and time is in seconds
P = 4610.7 × 37 / ( 3.6 × 60) = 789.80 W
where (3.6 × 60 ) is the time in seconds
To solve this problem it is necessary to apply Snell's law and thus be able to calculate the angle of refraction.
From Snell's law we know that
Where,
n_i = Refractive indices of each material
= Angle of incidence
= Refraction angle
Our values are given as,
Replacing
Re-arrange to find
Therefore the angle will the beam make with the normal in the glass is 26°
Answer:
Explanation:
Rate of Change
When an object moves at constant speed v, the distance traveled at time t is
We know at time t=0 two friends are at the intersection of two perpendicular roads. One of them goes north at speed v and the other goes west at constant speed w (assumed). Since both directions are perpendicular, the distances make a right triangle. The vertical distance is
and the horizontal distance is
The distance between both friends is computed as the hypotenuse of the triangle
We need to find d', the rate of change of the distance between both friends.
Plugging in the above relations
Solving for d
Differentiating with respect to t
The problem is solved using Pythagoras' Theorem, representing the two travel paths forming a right triangle. The rate at which the distance increases between two points moving perpendicularly can be found by differentiating the resulting equation, which yields the expression sqrt[(v^2)+(u^2)].
The question is about the rate at which the distance between you and your friend is increasing at time t. It's a typical problem in kinematics. Because the roads are perpendicular to each other, we can solve the problem using Pythagoras' Theorem which states that in a right-angled triangle, the square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides.
Let's denote the distance you've traveled as D1 = v*t (because distance = speed * time) and the distance your friend has travelled D2 = u*t. The distance between you can be computed using Pythagoras' Theorem as D = sqrt(D1^2 + D2^2). Hence, D = sqrt[(v*t)^2 + (u*t)^2]. Differentiating D with respect to t using the chain rule will give us the rate at which the distance between you is increasing, which is sqrt[(v^2)+(u^2)].
#SPJ11
The gravitational force minus any contact forces acting on an object
The difference between the normal force and the gravitational force acting on an object
The sum of all the forces acting on an object in the same direction
The sum of all forces acting on an object in the same direction is described for the net force acting on an object.
Example : If two forces (2 kids pushing in the same direction to move the object big box) act on an object (big box) in the same direction, then the net force is equal to the sum of the two forces. If the kids pushed in the opposite direction, the net force will not occur.
Hence, Option D is the correct answer.
Learn more about Net force,
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Answer:
The sum of all the forces acting on an object in the same direction.