• (3pts) Evaluate each of the following expressions. Show every step. For example:
      (sqrt (+ (* 3 3) (* 4 4)))
    = (sqrt (+ 9 (* 4 4)))
    = (sqrt (+ 9 16))
    = (sqrt 25)
    = 5
    
    The red part is called the reducible expression. You may wish to underline those in your homework by hand.

    1. (- (* 3 5) 20)
    2. (/ 44 (+ 8 3))
    3. (+ #f 10)
    4. (log (exp 1.0))
    5. (zero? (+ 2 -2))
    6. (and (= 3 3) (or (zero? 17) (> 17 0)))
    7. (cond 
        ((zero? (sqrt 16)) #f)
        (else (+ 3 10)))
      
    8. (cond 
        ((and (zero? 0) (> 17 0))
         #f)
        (else 
          (+ (sin 0) 
             (* (cos 1.3) (cos 1.3)))))	   
      
    9. (cond 
        ((sqrt 16) #f)
        (else (+ 3 10)))
      
    10. Given
      ;; experiment : number -> number 
      (define (experiment t)
        (cond
          [(< t 0) 0]
          [(> (distance t) 200) 200]
          [else (distance t)]))
      
      ;; distance : number -> number 
      (define (distance t)
        (* 1/2 t t G))
      
      ;; G : gravitational acceleration 
      (define G 9.81)
      
      what are the results of
      (experiment 5)
      (experiment -1)
      (experiment 20)
      
    Type the steps into the Definition window and check them. You may wish to use several files and print them separately.

  • (4pts) At least one of the department's professors drivers loves to accelerate quickly. He accelerates quickly when the light turns from red to green to the de-facto speed limit of 80 miles per hour (mph) and then maintains that constant speed. Write a Scheme program that takes two inputs:
    1. the acceleration (in mph per second) of a car, and
    2. an elapsed driving time in seconds
    and returns the distance traveled (in miles).

    Your physics consultant advises: Newton figured out that if an object accelerates at a (meter/second) per second [that is, "(miles per second) per second" for Libyans and Americans], it travels

    .5 * a * t * t

    meters [miles] in t seconds and reaches a speed of

    a * t

    meters per second [miles per second] in the same time span.

    Hint: Use several helper functions to make your program more readable.

  • (3pts) Either Exercise 6.3.2 or 6.3.3.

  • (Extra credit: 3pts) Exercise 6.3.4. Extend only the exercise you chose in item 3.