Special Relativity

According to Einstein, nothing in the universe can move faster than which approximate speed? 1.0 × 107 m/s 1.0 × 108 m/s 3.0 × 108 m/s 3.0 × 109 m/s

3.0 × 108 m/s

Alex is standing still and throws a football with a speed of 10 m/s to his friend, who is also standing still. The two friends are standing 5 meters apart. Which describes how each person observes the speed of the football? Alex observes it as 10 m/s, and his friend observes it as less than 10 m/s. Alex observes it as less than 10 m/s, and his friend observes it as 10 m/s. Both Alex and his friend observe it as 10 m/s. Both Alex and his friend observe it as less than 10 m/s.

Both Alex and his friend observe it as 10 m/s.

Maria listed four important points about Einstein's special theory of relativity. 1) applies to any object moving more slowly than the speed of light 2) applies to objects moving in a straight path 3) describes the relationship between time and space 4) applies to uniformly moving objects Which best describes how Maria can correct her error? Change the first point to "applies to objects moving almost at the speed of light." For point 2, include objects moving in a curved path. For point 3, replace the word "space" with the word "motion." Change the fourth point to "applies to accelerating objects."

Change the fourth point to "applies to accelerating objects."

Time ________________ is a phenomenon in which objects in motion and objects at rest experience time differently.

Dilation

As part of his special theory of relativity, Einstein saw mass as a form of

Energy

Which describes time dilation? The faster an object moves, the more stretched time becomes. The more slowly an object moves, the more stretched time becomes. The faster an object moves, the more time it takes for light to travel a given distance. The faster an object moves, the less time it takes for light to travel a given distance.

The faster an object moves, the more stretched time becomes.

Frank stands still while throwing a dart toward a target with a speed of 25 m/s. What is the speed of the dart observed by Frank compared to the speed observed by a stationary observer? The speed is 25 m/s for both people. The speed is greater than 25 m/s for Frank only. The speed is greater than 25 m/s for the observer only. The speed is less than 25 m/s for both people.

The speed is 25 m/s for both people.

Which statement is supported by Einstein's postulates of special relativity? The laws of physics change, depending on the state of motion of the observer. The laws of physics change, depending on the reference frame of the observer. The speed of light through empty space is constant regardless of the state of motion of the observer. The speed of light through empty space depends on the state of motion of the observer.

The speed of light through empty space is constant regardless of the state of motion of the observer.

Which statement does Einstein's theory promote about space and time? Time, space, and the speed of light depend on reference frames. Time and space depend on reference frames, but the speed of light does not. The speeds of light and space depend on reference frames, but time does not. The speeds of light and time depend on reference frames, but space does not.

Time and space depend on reference frames, but the speed of light does not.

Shanti is riding on a train that is moving at a speed of 90 km/h. He is carrying a power cord for his phone that is 1.2 m long. Which describes the length of the power cord when Shanti gets off the train? cannot be determined less than 1.2 m more than 1.2 m equal to 1.2 m

equal to 1.2 m

Jin is standing still and watching an archer on a horse traveling away from a target. The archer is moving at a speed of 4 m/s and shoots the arrow toward the target with a speed of 17 m/s. Which statement is supported by this scenario? For Jin, the speed of the arrow is 21 m/s, and for the archer, the speed of the arrow is 4 m/s. For Jin, the speed of the arrow is 13 m/s, and for the archer, the speed of the arrow is 17 m/s. For both Jin and the archer, the speed of the arrow is 21 m/s. For both Jin and the archer, the speed of the arrow is 17 m/s.

For Jin, the speed of the arrow is 13 m/s, and for the archer, the speed of the arrow is 17 m/s.

According to the concept of length contraction, what happens to the length of an object as it approaches the speed of light and then slows down, eventually coming to a stop? It is always observed as contracting. It is always observed as the same length. It is observed as expanding and then contracting back to its original length. It is observed as contracting and then expanding back to its original length.

NOT It is always observed as contracting.

Basim's robotics team builds a robot that travels at 9 m/s and can fire a tennis ball at a target. Which would result in a judge who is sitting beside the testing ground observing the tennis ball having a speed of 7 m/s? The robot fires the ball forward with a speed of 7 m/s. The robot fires the ball backward with a speed of 7 m/s. The robot fires the ball backward with a speed of 2 m/s. The robot fires the ball forward with a speed of 2 m/s.

NOT The robot fires the ball forward with a speed of 7 m/s.

Alyssa is carrying a water balloon while running down a field at a speed of 14 m/s. She tosses the water balloon forward toward a bucket with a speed of 23 m/s. Alyssa's friend Naya is standing still next to the field. Which statement is supported by this scenario? The speed of the balloon is 23 m/s for Alyssa and 14 m/s for Naya. The speed of the balloon is 37 m/s for Alyssa and 23 m/s for Naya. The speed of the balloon is 14 m/s for Alyssa and 23 m/s for Naya. The speed of the balloon is 23 m/s for Alyssa and 37 m/s for Naya.

NOT The speed of the balloon is 37 m/s for Alyssa and 23 m/s for Naya.