Answer:
The answer is "telescopes".
Explanation:
Throughout ancient times, astronomical observatories have indeed been available, and so many historical locations were reserved for astronomical observations. All contemporary astronomers lacked within those older telescopes were lenses until 1610. A telescope is indeed an instrument used to view far-off objects. Telescopes often are being used to look at planets and stars.
Answer: The angle between force and displacement should be θ = 90° for minimum work. The angle between force and displacement should be θ = 0° for maximum work.
Answer:-q
Explanation:
Given
Capacitor is charged to a battery and capacitor acquired a charge of q i.e.
+q on Positive Plate and -q on negative Plate.
If the plate area is doubled and the plate separation is reduced to half its initial separation then capacitor becomes four times of initial value because capacitor is given by

where A=area of capacitor plate
d=Separation between plates
This change in capacitance changes the Potential such that new charge on the negative plate will remain same -q
Answer:
2000 ohms
Explanation:
Resisters in series just add.
Rt = R1 + R2 + R3
R1 = 650 ohm
R2 = 350 ohm
R3 = 1000 ohm
Rt = 650 + 350 + 1000
Rt = 2000 ohms.
The correct answer is - CaCl2
The calcium chloride is a salt, an inorganic compound. Its formula is CaCl2, with Ca being calcium, Cl being chloride, and the number 2 representing the number of chloride molecules.
The calcium chloride is a white colored crystalline solid when it is at room temperature, and it is highly soluble in water, acetone, and acetic acid. It has a molar mass of 110.98 g/mol, density of 2.15 g/cm³, and melting point at 772 °C.