Explain what are wave fronts?

521

---

Explain the law of machines?

571

---

Explain what affect does electricity have on soil?

540

---

Explain the characteristics of dead stars?

511

---

Explain what is meant by 4th dimension?

499

---

Explain what is centrifugal force?

533

---

Explain how do fireworks turn into shapes like hearts and stars?

577

---

Explain what is neutral buoyancy?

522

---

Explain how much does automotive oil weigh?

469

---

Name the element which has the simplest absorption spectrum?

487

---

Tell me how are amps and watts related?

488

---

Explain the balanced field takeoff?

530

---

Explain what is larger the force the earth exerts on you or the force you exert on the earth?

484

---

Explain the cause of brownian motion?

527

---

Explain how do you convert from pascal to torr?

473

---