A physics commuter student is about to leave their house with 75 mu s before the

Question

A physics commuter student is about to leave their house with 75 mu s before the class begins on campus which is 11 miles away. What minimum speed would they have to travel at to make it to class on time? The Enterprise flies past Kronos (the Klingon home world) with a speed of 0.968c relative to the surface of the planet. When the starship is 2000 km directly over the Kahless Institute of Technology, a very bright signal light on the university campus blinks on and off. A Klingon student observes the signal duration to be 0.5 s. What is the duration of the light pulse as seen by Spock on the Enterprise? A newly discovered sub-atomic particle streaking across the laboratory at 0.98c was observed to exist for 30 nsec. What will its lifetime be measured to be when the particle is at rest? A supertrain (proper length, 100 m) travels fast enough to fit in a tunnel (proper length, 50 m) with 25 m to spare. What is its speed to three significant figures as a fraction of the speed of light? A spaceship moves away from the Earth at 0.6c and fires a shuttle craft in the forward direction at 0.6c relative to the ship. The pilot of the shuttle craft launches a probe at forward speed 0.6c relative to the shuttle craft. Determine (a) the speed of the craft relative to the Earth and (b) the speed of the probe relative to the Earth. As seen from earth, two ships are moving away at speeds of 0.95c and 0.8c (in the same direction). How fast will the slower ship see the other pulling away? Two spaceships move towards each other at speeds of 0.9c and 0.7c relative to an earth observer. (a) What speed will each determine for the other? (b) If they are one light year away from each other by the earth observer's reckoning, then how long will it take for the two ships to meet according to the same earth observer? A spring whose spring constant is 2000 N/m is compressed by 5 cm. By how much does its mass increase in its compressed state? An electron and a positron (anti-electron) annihilate in a particle physics laboratory. What is the minimum amount of energy released? (m_e = 9.11 times 10^-31 kg)

Explanation / Answer

32.

d = distance to be travelled = 11 miles = 11 x 1609.34 m

t = time = 75 x 10-6 sec

speed is given as

v = d/t = (11 x 1609.34 )/(75 x 10-6 )

v = 2.4 x 108 m/s

34.

v = speed = 0.98 c

To = life time while moving = 30 x 10-9 sec

T = lifetime while at rest = ?

using the formula

T = To/sqrt(1 - (v/c)2)

T = (30 x 10-9 ) /sqrt(1 - (0.98 c/c)2)

T = 1.51 x 10-7 sec

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.