What instrument use lenses or mirrors to collect and focus light from distant objects?

What is the work done by gravity when a 2.0kg ball falls to the floor from the height of 1.50m? Is it positive or negative? Explain

An elevator exerts a force of 8000 N to lift the passengers 15 m. How much work is the elevator doing? The elevator is doing J of work.

A scientist heats a piece of iron until it is glowing white-hot. he places the metal inside a metal box. he removes all of the air from the inside of the box.

An object is going 22 m/s and is 3 kg. find momentum

Which elements does not exist as a diatomic molecule?

The hinge at A and cable BDC support beam ABC. Cable BDC passes over the pulley D that is pinned to the ceiling. (Assume that the + x-axis is to the right and the + y-axis is up along the page.

The "zone of avoidance" a) Accounts for the absence of any planet between the orbits of Mars and Jupiter Prevents collisions between planets in the Solar System.

Electric current is ...

What type of ethic is life-centered and views humans as just one component life on Earth

Which formula describes acceleration? m/s^2 m/s s/m m2