How can the momentum of a particle increase by $5 \%$ with only a $1 \%$ increase in speed?

The energy of fission is the kinetic energy of its products. What becomes of this energy in a commercial power reactor?

In the preceding exercise, if the stick is moving in a direction along its length (like a properly thrown spear), how long will you measure its length to be?

As a meterstick moves past you, your measurements show its momentum to be twice its classical momentum and its length to be $1 \mathrm{~m}$. In what direction is the stick pointing?

Light is reflected from a moving mirror. How is the reflected light different from the incident light, and how is it the same?

An object is moving vertically, will any contraction take place in a horizontal direction?

A person riding on the roof of a freight train throws a ball forward. (a) If we ignore air drag and relative to the ground, is the ball moving faster or slower when the train is moving than when it is standing still? (b) Relative to the freight car, is the ball moving faster or slower when the train is moving than when the train is standing still?

The formula that relates the speed, frequency, and wavelength of electromagnetic waves, $v=f \lambda$, was known before relativity was developed. Relativity has not changed this equation, but it has added a new feature to it. What is that feature?

Write a short story that describes a situation involving the heart when the sympathetic and parasympathetic nervous systems work together to maintain homeostasis.

If stationary observers measure the shape of a passing object to be exactly circular, what is the shape of the object when viewed face-on by observers on board the object, traveling with it?

What occurs when a nitrogen nucleus captures an extra neutron?

What classical idea about space and time did Einstein reject?

How do the measured densities of a body compare at rest and in motion?

Pretend that the starship Enterprise in the previous problem is somehow traveling at $c$ with respect to the Earth, and it fires a drone forward at speed $c$ with respect to itself. Use the equation for the relativistic addition of velocities to show that the speed of the drone with respect to the Earth is still $c$.