They are the same weight though the rest of the world might question why you are still using the outdated imperial system...

If a glass of water has ice cubes in it and is filled to the brim, what happens to the water level when the ice cubes melt?

easy...

water level is goin down, because ice has more volume then the related water.

an answer to an unasked question:

water has his highest density (and so its lowest volume) at +4°C, its called the "anomaly of water" (but some other substances have this anomaly also, i.e. Plutonium).

If your driving a car at the speed of light, and you turn on the headlights, does anything happen?

Would it be possible for a solar powered car to travel faster than light?

What do people in China call their good plates?

Why can magicians make things dissapear into thin air, but not thick air?

And my personal favourite:

If you try to fail, and succeed what have you done?

Yes, a solar powered car can travel at the speed of light because the car can be stationary while charging.

Jasper already answered the good plates one.

For the last one, it depends on your definition of thick. If you mean thick as in hot and humid, then they can make things dissapear into thin air as well as thick air. However, since most magicians perform indoors with all the different enviromental controls, they will often just be in 'thin' air while the are doing their witchcraft.

"This question and all others about experiences at the speed of light do not have a definitive answer.  You cannot go at the speed of light so the question is hypothetical.  Hypothetical questions do not have definitive answers.  Only massless particles such as photons can go at the speed of light.  As a massive object approaches the speed of light the amount of energy needed to accelerate it further increases so that an infinite amount would be needed to reach the speed of light."

-Copy/Paste from www.math.ucr.edu

But in theory, my answer would be that you would see nothing. Now if the driver were traveling just 0.0000000001 less than the speed of light, the headlights, in the drivers perspective, would be accelerating away from him at the speed of light. So you would think that it would accelerate only 0.0000000001 faster than you (since you already at near-light speeds), but in fact, in your perspective it would dart away from you at the speed of light. Everything would be Doppler shifted and would look fish-eyed (bent) and blue (towards the ultraviolet). Time within the spacecraft would appear normal. Your heart would still beat at 70 beats per second, and a cesium 133 atom would still vibrate at 9,192,631,770 periods per second. But from an outside observers perspective, it would appear that time has slowed, or even frozen for the spacecraft (because in one of Einstein's equation, it stated that there is link between motion through space, and the passage of time. Or, in other words, the more you have of one, the less you have of the other). So if you traveled at the speeds near the speed of light, most of your energy is directed in the form of movement through space, thus theres little to no energy in time, thus you can infer that it appears that the spacecraft is frozen in time (but not in space of course).

To be a heartbreaker, there are many obstacles that make space travel near the light speeds impossible. One being Einstein's famous equation, E = mc², which limits the possibility of near light travel. In this equation, E is energy, m is mass and c is the speed of light. According to this equation, mass and energy are the same physical entity and can be changed into each other. Because of this equivalence, the energy an object has due to its motion will increase its mass. In other words, the faster an object moves, the greater its mass. This only becomes noticeable when an object moves really quickly. If it moves at 10 percent the speed of light, for example, its mass will only be 0.5 percent more than normal. But if it moves at 90 percent the speed of light, its mass will double. As an object approaches the speed of light, its mass rises precipitously. If an object tries to travel 186,000 miles per second, its mass becomes infinite, and so does the energy required to move it. For this reason, no normal object can travel as fast or faster than the speed of light.

If somehow we can bypass that roadblock by tapping into a infinite energy source, there are many other problems. Like when elements start to travel at fast speeds (at 20% the speed of light for example), it starts to decay and becomes radioactive. Thus endangering the crew of radiation exposure and equipment failure. 

Aye, what the heck. All we need is Marty's delorean, a few copper wires, high powered juicer, and put in the year, month, and day, and whoosh. Let's just not take leap year into account though or that time travel has nothing to do with space travel. Everything is so much eaiser than it looks.

Now shush and think happy thoughts!