Why is most space exploration accomplished with spacecraft that do not have astronauts on board

Determine the correct name for the compound, c3h8. in organic chemistry, this is referred to as propane. a. tricarbon hexahydride b. tricarbon octahydride c. tetracarbon octahydride d. tetracarbon hexahydride

Name and classify Si and Sb. A) Sarium and siobium are metals. B) Silicon and antimony are metalloids. C) Silinium and sirbonium are non-metals. D) Silver and seaborgium are transition metals.

How to solve for h using the formula eg=mgh?

An object has a kinetic energy ke, and potential energy pe. it also has a rest energy e0. what is the object's total energy e?

Specific gravity is the density of an object compared to water. a. True b. False

A boulder on top of a cliff has a potential energy of 12400J. How high above is the boulder?

If the graph represents speed what is measured on the x and y axes

It is difficult to lift a heavy stone than the lighter one on the earth, why?

The vapor pressure of ethanol at 25 degrees C is 7.83 kPa. Calculate the vapor pressure in atm. Round answer to 3 significant digits.

According to Newton's second law of motion acceleration or an object depends upon the ___ of the object and the ___ Acting on it. I'm confused on what the blanks are. I can't find them.