Question
2. A train starting from rest reaches a speed of 31.26 m/s in 19.1 seconds. What is the train's acceleration? 3. In the year 456 N.V., you are an astronaut learning about a newly discovered planet. In order to determine the planet's gravitational acceleration, you toss a ball up into the air with an initial speed of 11.7 m/s and time how long it takes to get back to you. You calculate a g of 3.9 m/s. You will find this problem fairly simple if you analyze it with a diagram/cartoon as was done in class. I've left you space for this to the right of part a a. Fill in the following table, showing the velocity of the ball after the given number of seconds. Remember that velocity is a vector and uses signs. Remember also that the moment you let go of the ball is zero seconds. Timev 1s 2s 3s 4s What was the balls velocity when it passed you again? What is the value of g when the ball reaches the ground? What was the balls velocity at the very top of its trip? a. b. C.
Explanation / Answer
2] by first equation of motion,
v = u + at
31.26 = 0 + 19.1 a
a = 31.26/19.1
= 1.64 m/s^2 answer
