Question

1. Flybynite Airlines takes 3 hours to fly from Baltimore to Denver at a speed of 800 km/hr. To save fuel, management orders its pilots to reduce their spped to 600km/hr. How long will it now take passengers on thhis route to rech their destination?

use d=rt

a. 3.5 hr

b. 3.75hr

c. 4hr

d. 5hr

2. A sports car accelerates from 0km/hr to 100km/hr in 4 seconds. What it its average acceleration.

Average acceleration is given by (be very careful of units)

vf-vi

-----

t

a. 25 km/hr

b. 25km/hr^2

c. 6.95X10^-3

d. 6.95m/s^2

3. Suppose you read in a tabloid newspaper that "experts have idscovered a new planet with a distance from the SUn of 1 AU and a period of 3 years. use kepler's third law to determine if this can be true.

T^2=A^3

Where A is in AU, and T is in Earth years. Using the given data we should find

a. Yes, the data satisfy Kepler's third law

b. Yes, the data could satisfy Kepler's third law if the period were given in months instead of years.

c. No the data do not satisfy Kepler's third law. Either the period or the distance (or bothe) are wrong.

d. No, the data do not satisfy Kepler's third law, but the data do satisfy Kepler's second law

4. Suppose you discover a new dwarf pllanet in our Solar system with a semimajor axis of 46.4AU. What is its period (in Earth years?)

T^2=A^3

We are given a semimajor axis and asked for a period. This screams to us "Kepler's third law!"

Where A is in AU, and T is in Earth years.

a. 129 years

b. 316 years

c. 1024 years

d. 3 x 104 years

Answer 1

1. d = v t

d = (800 km/hr) (3 hr)

d = 2400 km

distance between Baltimore and Denver is 2400 km.

now v' = 600 km/hr

t' = d / v' = 2400 / 600

t' = 4 hr

Ans(C)