Answer:
A lens
Explanation:
A lens forms images when light passes Through it bending the rays of in the process.A phenomena called refraction and the speed of light changes in the process because it enters a medium since it's wavelength is reduced.
Answer:
Therefore the ratio of diameter of the copper to that of the tungsten is

Explanation:
Resistance: Resistance is defined to the ratio of voltage to the electricity.
The resistance of a wire is
- directly proportional to its length i.e

- inversely proportional to its cross section area i.e

Therefore

ρ is the resistivity.
The unit of resistance is ohm (Ω).
The resistivity of copper(ρ₁) is 1.68×10⁻⁸ ohm-m
The resistivity of tungsten(ρ₂) is 5.6×10⁻⁸ ohm-m
For copper:


......(1)
Again for tungsten:

........(2)
Given that
and 
Dividing the equation (1) and (2)

[since
and
]



Therefore the ratio of diameter of the copper to that of the tungsten is

QUESTION -
In which direction does energy flow in an ecosystem ?
ANSWER -
The flow of energy in an ecosystem is best described as energy moving in one direction from the sun to the producers then to the consumers. Explanation; Energy flow is the amount of energy that moves through successive trophic levels of a food chain in an ecosystem
From harmful radiation from our sun!!!!!
Answer:
616.223684211 N
Explanation:
= Resistive force on the wheel = 115 N
F = Force acting on sprocket
= Radius of sprocket = 4.75 cm
= Radius of wheel = 25 cm
Moment of inertia is given by

Torque

Torque is given by

The force on the chain is 616.223684211 N