What is the difference between a lens and a mirror?

1021

---

When gravity is the only force acting on an object the object is in what?

1033

---

Which way do twin screw props on a boat rotate when propelling the boat forward?

872

---

A car traveling at 30mph ( =13.4 m/s) & it slams on its brakes. ( The car is decelerated by the force of the friction 0.7..f *distance x. (Weight=mg) how far will the cargo before it stops?

825

---

What does hull speed mean?

1085

---

This person established the one fluid theory of electricity and performed some of the first investigations into electrical grounding and insulation:

888

---

What is a positron?

978

---

Does solar radiation contain a complete spectrum of all forms of electromagnetic radiation?

867

---

How do you magnetize metal?

964

---

What is geocentric?

1001

---

Does a soccer ball go faster in the air on a cold or hot day?

949

---

how many neutrons and how many protons are present in a single deuterium nucleus?

1004

---

Why do you not collapse under the pressure created by the atmosphere?

987

---

How is nuclear fission different from nuclear fusion?

1001

---

What do you mean by diffraction and what is/are the proper condition/conditions for it?

1033

---