What event was seen as a symbol of the gradual relationship improvements between the United States and the Soviet Union as the Cold War was coming to an end?
A. The Soviet space center and the US space center signed a treaty agreeing to put the past behind them and work together for future space endeavors.
B. A handshake that occurred between the commanders of a US and Soviet space craft that were involved in a joint moon mission.
C. Astronauts from both countries taking a trip to the moon together aboard one space craft.
D. A male astronaut from the Soviet Union and a female astronaut from the US walked on the moon together.

Amass m = 74 kg slides on a frictionless track that has a drop, followed by a loop-the-loop with radius r = 18.4 m and finally a flat straight section at the same height as the center of the loop (18.4 m off the ground). since the mass would not make it around the loop if released from the height of the top of the loop (do you know why? ) it must be released above the top of the loop-the-loop height. (assume the mass never leaves the smooth track at any point on its path.) 1. what is the minimum speed the block must have at the top of the loop to make it around the loop-the-loop without leaving the track? 2. what height above the ground must the mass begin to make it around the loop-the-loop? 3. if the mass has just enough speed to make it around the loop without leaving the track, what will its speed be at the bottom of the loop? 4. if the mass has just enough speed to make it around the loop without leaving the track, what is its speed at the final flat level (18.4 m off the ground)? 5. now a spring with spring constant k = 15600 n/m is used on the final flat surface to stop the mass. how far does the spring compress?