question1:You wish to travel from downtown New York City (NYC) to downtown Washington DC (DC), a distance of 330 km. You consider two options: train and plane. The high-speed train takes 1.8 hr, plus 30 min in stations. The airplane flies the 330 km (airport to airport) in just 25 min, but the drive to the NYC airport takes 30 min, you must arrive three hours before departure time, the plane waits 15 min for takeoff, and it takes 20 min to get your luggage and drive into DC. Find the train's track speed, the plane's flying speed, the total travel time for each option, and the overall average speed for each option.
train track speed ? km/h
plane flying speed ? km/h
train travel time ? h
plane travel time ? h
train trip average speed ? km/h
plane trip average speed ? km/h
question2:You drive from New York City to Washington DC, by car. You drive in traffic for the first hour at an average 30 km/hr. You cover the next 250 km in 3.3 hr, and then drive the remaining 30 km into Washington in 30 min. Find your total time and average speed.
total time
? hr
average speed
? km/hr
question3:A car starts from rest and maintains an acceleration of 3.7 (km/hr)/s for 7 s. How fast is it going at the end of the 7 s?
? km/h
question4:A car is moving at 40 km/hr. The driver then presses harder on the accelerator, causing an acceleration of 1.50 (km/hr)/s, which she maintains for 4 s. How fast is the car going at the end of the 4 s?
? km/hr
question5:You drop a rock down a well and hear a splash 9 s later. As Charlie Brown would say, the well is "nine seconds deep." But how many meters deep is it, assuming that air resistance is negligible and that the time for sound to travel back up the well is also negligible?
? m
question6:You drop an apple out of a fifth-story window. When does it pass the fourth-story window, 4 m below?
? seconds after being dropped
question7:A car speeds up from rest, along a straight highway. Its acceleration is unchanging. How much farther (measured from the starting point) does it get in 8 s, as compared with 4 s?
(distance in 8 s / distance in 4 s) = ?
question8:On the planet Mars, a free-falling object released from rest falls 4 m in 1 s and is moving at 8 m/s at that time. How fast would such an object be moving after the following times?
5 s
? m/s
9 s
? m/s
question9:You drop a rock off a cliff and note that it hits the ground below in 8 s. How high is the cliff, assuming that the air is so thin that air resistance can be neglected during the entire fall?
? m
Unless the air is extremely thin, air resistance will not be negligible. What does this tell you about your calculation of the cliff's height: Is the cliff actually higher, or is it lower, than your calculated answer?
Higher/Lower
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