MEDIUM
JEE Main
IMPORTANT
Earn 100

Calculate the ratio of the drag force on a jet flying at 1200 km h-1 at an altitude of 10 km to the drag force on a prop-driven transport flying at half that speed and altitude. The density of air is 0.38 kg m-3 at 10 km and 0.67 kg m-3 at 5.0 km. Assume that the air planes have the same effective cross-sectional area and drag coefficient C.

Important Questions on Force and Motion-II

HARD
JEE Main
IMPORTANT
Principles Of Physics International Student Version>Chapter 6 - Force and Motion-II>Problems>Q 40
In downhill speed skiing, a skier is retarded by both the air drag force on the body and the kinetic frictional force on the skis. (a) Suppose the slope angle is  θ=40.0°, the snow is dry snow with a coefficient of kinetic friction  μk=0.0380 the mass of the skier and equipment is m=85.0 kg, the cross-sectional area of the (tucked) skier is  A=1.30 m2 the drag coefficient is C=0.150. and the air density is 1.20 kg m-3. (a) What is the terminal speed? (b) If a skier can vary C by a slight amount  dC by adjusting, say, the hand positions, what is the corresponding variation in the terminal speed?
HARD
JEE Main
IMPORTANT
Principles Of Physics International Student Version>Chapter 6 - Force and Motion-II>Problems>Q 41
A cat dozes on a stationary merry-go-round at a radius of 6.0 m from the center of the ride. Then, the operator turns on the ride and brings it up to its proper turning rate of one complete rotation every 6.0 s. What is the least coefficient of static friction between the cat and the merry-go-round that will allow the cat to stay in place without sliding?
EASY
JEE Main
IMPORTANT
Principles Of Physics International Student Version>Chapter 6 - Force and Motion-II>Problems>Q 42
Suppose the coefficient of static friction between the road and the tires on a car is 0.60 and the car has no negative lift. What speed will put the car on the verge of sliding as it rounds a level curve of 32.0 m radius?
HARD
JEE Main
IMPORTANT
Principles Of Physics International Student Version>Chapter 6 - Force and Motion-II>Problems>Q 43
What is the smallest radius of an unbanked (flat) track around which a bicyclist can travel if her speed is 35 km h-1 and the μs between tires and track is 0.40?
EASY
JEE Main
IMPORTANT
Principles Of Physics International Student Version>Chapter 6 - Force and Motion-II>Problems>Q 44
During an Olympic bobsled run, the Jamaican team makes a turn of radius 7.6 m at a speed of 96.6 km/h. What is their acceleration in terms of g?
HARD
JEE Main
IMPORTANT
Principles Of Physics International Student Version>Chapter 6 - Force and Motion-II>Problems>Q 45
A student of weight 667 N rides a steadily rotating Ferris wheel (the student sits upright). At the highest point, the magnitude of the normal force F→N on the student from the seat is 556 N. (a) Does the student feel 'light' or 'heavy' there? (b) What is the magnitude of F→N at the lowest point? If the wheel's speed is doubled, what is the magnitude FN at the (c) highest and (d) the lowest point?
HARD
JEE Main
IMPORTANT
Principles Of Physics International Student Version>Chapter 6 - Force and Motion-II>Problems>Q 46
A police officer in hot pursuit drives her car through a circular turn of radius 300 m with a constant speed of 75.0 km/h. Her mass is 55.0 kg. What are (a) the magnitude and (b) the angle (relative to vertical) of the net force of the officer on the car seat? (Hint: Consider both horizontal and vertical forces)
MEDIUM
JEE Main
IMPORTANT
Principles Of Physics International Student Version>Chapter 6 - Force and Motion-II>Problems>Q 47
A circular-motion addict of mass 80 kg rides a Ferris wheel around in a vertical circle of radius 12 m at a constant speed of 5.5 m/s. (a) What is the period of the motion? What is the magnitude of the normal force on the addict from the seat when both go through (b) the highest point of the circular path and (c) the lowest point?