A speedy tortoise can run with a velocity of 10.0 cm/s and a hare can run 20.0 times as fast. In a race, they both start at the same time, but the hare stops to rest for 2.00 minutes. The tortoise wins by a shell (20.0 cm). What was the length of the race?
[Ques. 2] A helicopter descends from a height of 600 m with uniform negative acceleration, reaching the ground at rest in 5.00 minutes. Determine the acceleration of the helicopter and its initial velocity.
[Ques. 3] A bicyclist starts down a hill with an initial speed of 2.0 m/s. She moves down the hill with a constant acceleration, arriving at the bottom of the hill with a speed of 8.0 m/s. If the hill is 12 m long, how long did it take the bicyclist to travel down the hill?
[Ques. 4] A boat moves at 10.0 m/s relative to the water. If the boat is in a river where the current is 2.0 m/s, how long does it take the boat to make a complete round trip of 1.00 km upstream followed by a 1.00 km trip downstream?
[Ques. 5] A 50-gram superball traveling at 25.0 m/s is bounced off a brick wall and rebounds at 22.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.50 ms, what is the average acceleration of the ball during this time interval?
[Ques. 6] A particle is moving with a constant acceleration of 4.0 m/s2 . Its speed at t = 1.0 s is 4.0 m/s and at t = 3.0 s it is 12.0 m/s. What is the area under the position-time graph for the interval from t = 1.0 s to t = 3.0 s?
a. 8.0 m/s
b. 8.0 m
c. 12 m
d. 16 m
e. 16 m/s2
[Ques. 7] A particle is moving at constant velocity. Its position at t = 1.0 s is 3.0 m and its position at t = 4.0 s is 15.0 m. What is the slope of the position-time graph for this particle?
a. 0, since this is a constant velocity situation.
b. 4.0 m/s
c. 4.0 m/s2
d. 9.0 m/s
e. 12 m/s2
[Ques. 8] The speed of an object is given by v = 5.00t2 +4, where v is in m/s and t is in s. What is the acceleration of the object at t = 2.00 s?
a. 5.00 m/s2
b. 9.00 m/s2
c. 10.0 m/s2
d. 14.0 m/s2
e. 20.0 m/s2
[Ques. 9] A problem may be solved more easily when alternative representations are used. The best strategy is to formulate representations in an order that assists in understanding the physical principles involved. Of the orders given below, the one that will work best most often is
a. pictorial representation, mathematical representation, tabular representation, mental representation.
b. pictorial representation, mental representation, mathematical representation, tabular representation.
c. mathematical representation, pictorial representation, tabular representation, mental representation.
d. mathematical representation, tabular representation, mental representation, pictorial representation.
e. mental representation, pictorial representation, tabular representation, mathematical representation.
[Ques. 10] A swimmer swims 20 laps in a north-south facing pool in 7.00 minutes. Her first lap is toward the north. Her displacement and average velocity are
a. 0; 0.
b. 0; 2.38 m/s, south.
c. 0; 2.38 m/s, north.
d. 1 000 m, south; 2.38 m/s, south.
e. 1 000 m, north; 2.38 m/s, north.
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