Choose the one alternative that best completes the statement or answers the ques
ID: 1442154 • Letter: C
Question
Choose the one alternative that best completes the statement or answers the question. A pot falls from a ledge and hits the ground 45 m below. The speed with which it hits the ground is about 30 m/s. about 120 m/s. about 60 m/s. more than 120 m/s. If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by about 10 m/s. 15 m/s. 5m/s. a variable amount. depends on its initial speed A ball is thrown upwards and return to the same position. Compared with its original speed after release, its speed when it returns about twice as much. the same. half as much. four times a much. If an object falling freely were somehow equipped with an odometer to measure the distance it travels, then the amount of distance it travels each succeeding second would be doubled. less and less each second. greater than the second before. constant. If a freely falling object were somehow equipped with a speedometer on a planet where the acceleration due to gravity is 20 m/s/s, then its speed reading would increase each second by 10 m/s. 40 m/s. 30 m/s. 20 m/s. depends on its initial speed At one instant a heavy object in air is moving upward at 50 meters per second. One second later its speed is approximately 55m/s. 50m/s. 60m/s. 40m/s. Disregarding air drag, how fast must you toss a ball straight up in order for it to take 2 seconds to return to the level from which you tossed it? 10 m/s 20 m/s 7.5 m/s 15 m/s 5m/s A car accelerates at 2 meters/s/s. Assuming the car starts from rest, how far will it travel in 10 s? 10m 2m 40m 100m 200mExplanation / Answer
here,
1)
height , h = 45 m
let the speed when it hits the ground be v
v = sqrt(2*g*h)
v = sqrt(2*9.8*45)
v = 30 m/s
the speed at bottom is A) about 30 m/s
2)
the speed increse per secoond is A) 10 m/s
as it is due to gravity
3)
when the ball return to same position , the speed is B the same as the original release speed
4)
as the accelration is constant and speed is varying
the distance is on increasing and C) greater than the seccond before