1: State how many significant figures there arein each of the following calculations, and indicate which is thelimiting value:

Part (a)(18.7)^2:

^1- 1 (limited by 2)

^2-4 (limited by 18.7

^3- 2 (limited by 18.7

^4- 3 (limited by 18.7)

^5- None of these.

Part (b) (1.60 ×10^-19)(3712) :

1- 2 (limited by 3712)

2- 2 (limited by 1.60)

3- 4 (limited by 3712)

4- 3 (limited by 1.60)

5- None of these.

2: A student witnesses a flash of lightning andthen t = 2.5 s later the student hears theassociated clap of thunder.

Part (a) Sound travels at 343m/s in the air. What distance from the student is the lightningstrike, in meters?

Part (b) Light travels at 3.0× 10⁸ m/s in the air. How long, t₁,in seconds did it take the light to reach the student's eyes afterthe lightning strike?

3: On a two-leg trip, a car travels the firstleg, a distance D₁ = 49 miles, in atime t₁ = 1.1 hours, and travels thesecond leg, a distance D₂ = 140 miles,in time t₂ = 2.25 hours. Refer to thefigure.

Part (d) What is the averagespeed for the whole trip in meters per second?

4: A student begins at rest and then walksnorth at a speed of v₁ = 0.55 m/s. Thestudent then turns south and walks at a speed ofv₂ = 0.92 m/s. Take north to be thepositive direction. Refer to the figure.

Part (a) What is the student'soverall average velocity v_avg, in meters persecond, for the trip assuming the student spent equal times atspeeds v₁ and v₂?

Part (b) If the studenttravels in the stated directions for 30.0 seconds at speedv₁ and for 20.0 seconds at speedv₂, what is the net displacement, in meters,during the trip?

Part (c) If it takes thestudent 5.0 s to reach the speed v₁ from rest,what is the magnitude of the student’s average acceleration, inmeters per second squared, during that time?