Which does not contain a lens?

eyeglasses

mirror

microscope

a floodlight

G: assume that, at a certain angular speed ω2, the radius r becomes twice l. find ω2.

A chunk of iron weighing a few kilograms flies into the inner Solar System, is captured by Earth's gravity, enters the atmosphere burning brightly, and lands on solid ground. Three different names apply to the different stages of its journey.

When a mass is placed on a spring with a spring constant of 15 newtons per meter, the spring is compressed 0.25 meter. How much elastic potential energy is stored in the spring?

Explain working of electric motor

Selena, who moves with the grace and fluid motions of a cat, has been described as A. porcine. B. equine. C. ursine. D. feline.

The current in a wire increases from 5 A to 10 A, what happens to its magnetic field? The field is twice as strong the distance of a charged particle from a wire changes from 10 cm to 20 cm, what happens to its magnetic field?

At a constant pressure and a temperature of 280 K, the gas in a cylinder has a volume of 10.0 liters. If the volume of the gas is increased to 20.0 liters, what is the new temperature? 2800 K 28 K 140 K 560 K

what must be the distance between source of sound and mountain to give an echo in 5 seconds?, (speed of sound at 0°c=33m/sec

What is the speed of a 50 g rock if its de Broglie wavelength is 3.32 x 10?

Leanne is riding a bike. The forward force from her pedalling is 18N. There is a backward force of 6N from friction and a backward force of 12N from air resistance. Does the speed of the bike increase, decrease or not change?