Answer:
W = 0
Explanation:
We are given with, a construction worker is carrying a load of 40 kg over his head and is walking at a constant velocity. He travels a distance of 50 m.
The work done by an object is given by :

F = ma
So,

m is mass
a is acceleration
d is displacement
The worker is moving with constant velocity, its acceleration will be 0. So, the work done by the worker is 0.
Answer:
(c) The planet must have a mass about the same as the mass of Jupiter,
(d) The planet must be closer to the star than Earth is to the Sun.
Explanation:
Astrometry is the ideal method to detect high-mass planets that are close to their star. That is because the gravitational effect that it will have the planet over its host star will be greater. This effect can be seen as a wobble in the star as a consequence of how they orbit a common center of mass¹. The center of mass will be closer to the most massive object, So, in the case of an extrasolar planet with masses like Jupiter (Jovian), this point will be a little bit farther from the star, making the wobble more notable than in a system with a low-mass planet.
Key terms:
Astrometry: study of the position of the stars over time in the sky.
¹Center of mass: a geometrical point in which the mass from a whole system is summed.
Answer:
<em>A. 751 ohm</em>
Explanation:
Impedance: <em>This is the total opposition to the flow of current in an a.c circuit by any or all of the three circuit elements ( R, L, C). The unit of impedance is Ohms (Ω). The impedance in a parallel circuit is gives a s</em>
<em>Z = RXₐ/√(Xₐ² + R²)............................... Equation 1</em>
<em>Where Z = The impedance of the a.c circuit, Xₐ = capacitive reactance, R = resistance.</em>
<em>Given: Xₐ = 962 Ω, R = 1200 Ω</em>
<em>Substituting these values into equation 1,</em>
<em>Z = 962×1200/√(962² + 1200²)</em>
<em>Z = 1154400/√(925444 + 1440000)</em>
<em>Z = 1154400/√(925444+1440000</em>
<em>Z = 1154400/1538</em>
<em>Z = 750.59 Ω</em>
<em>Z≈ 751 Ω</em>
<em>Therefore the impedance of the circuit = 751 Ω</em>
<em>The right option is A. 751 ohm</em>
Answer:
A jack is used to <u>lift</u> the force.
I think that's the answer. I don't really understand the question.
Answer:
112.06 kg - Thats heavy !
Explanation:
Let's do force balance here. Let the object of our interest be George. The forces acting on him are the tension in the upward direction, his weight in the downward direction and the centrifugal force in the downward direction. Considering the upward and downward directions on the y-axis and f=given the fact that George doesn't move up or down, the forces are balanced along the y-axis. Hence doing force balance:
magnitude of forces upward =magnitude of forces downward
i.e., Tension(T) = Weight(mg) + Centrifugal force (mv²/r)
where: 'm' is the mass of George, g is the acceleration due to gravity (9.8 m/s²). v is the speed with which George moves (14.1 m/s) and r is the radius of the circle in which he's moving at the instant (Here since he's swinging on the rope, he moves in a circle with radius as the length of the rope and hence r=7.3m).
therefore, T = m (9.8 + (14.1)²/7.3) = 4150 N
Therefore, m = 112.06 kg