Home
Class 12
PHYSICS
Suppose while sitting in a parked car, y...

Suppose while sitting in a parked car, you notice a jogger approaching towards you in the side view mirror of R = 2 m. If the jogger is running at a speed of 5 `ms^(-1)`, how fast the image of the jogger appear to move when the jogger is (a) 49 m, (b) 59 m away.

Text Solution

Verified by Experts

`(a) 1/(450) ms^(-1), (b) (1)/(660) ms^(-1)`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    KUMAR PRAKASHAN|Exercise SECTION-B (NUMERICALS)(NUMERICAL FROM TEXTUAL EXERCISE)|45 Videos

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    KUMAR PRAKASHAN|Exercise SECTION-B (NUMERICALS)(NUMERICAL FROM .DARPAN. BASED ON TEXTBOOK )|12 Videos

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    KUMAR PRAKASHAN|Exercise SECTION - A (TRY YOURSELF)|74 Videos

  • MOVING CHARGES AND MAGNETISM

    KUMAR PRAKASHAN|Exercise SECTION D (MCQs ASKED IN COMPETITIVE EXAMS)|34 Videos

  • SAMPLE QUESTION PAPER

    KUMAR PRAKASHAN|Exercise PART-B SECTION-C|5 Videos

Similar Questions

Explore conceptually related problems

Suppose while sitting in a parked car, you notice a jogger approaching towards you in the side view mirror of R = 2 m. If the jogger is running at a speed of 5 ms^(-1) , how fast the image of the jogger appear to move when the jogger is (a) 39 m, (b) 29 m, (c) 19 m, and (d) 9 m away.

Suppose while sitting in a parked car, you notice a jogger approaching towards you in the side view mirror of R = 2 m. If the jogger is running at a speed of 5 m s^(-1) , how fast the image of the jogger appear to move when the jogger is (a) 39 m, (b) 29 m, (c) 19 m, and (d) 9 m away.

Knowledge Check

  • A car is moving with at a constant speed of 60 km h^(-1) on a straight road. Looking at the rear view mirror, the driver finds that the car following him is at a distance of 100 m and is approaching with a speed of 5 km h^(-1) . In order to keep track of the car in the rear, the driver begins to glance alternatively at the rear and side mirror of his car after every 2 s till the other car overtakes. If the two cars were maintaining their speeds, which of the following statement (s) is // are correct?

    A
    The speed of the car in the rear is 65 km `h^(-1)`.
    B
    In the side mirror, the car in the rear would appear to approach with a speed of 5 km `h^(-1)` to the driver of the leading car.
    C
    In the rear view mirror, the speed of the approaching car would appear to decrease as the distance between the cars decreases.
    D
    In the side mirror, the speed of the approaching car would appear to increase as the distance between the cars decreases.

    • Similar Questions

    Explore conceptually related problems

    A kite is moving horizontally at a height of 151.5 meters. If the speed of kite is 10 m/s, how fast is the string being let out , when the kite is 250 m away from the boy who is flying the kite ? The height of boy is 1.5 m.

    A thief is running away in a car with velocity of 20 m//s . A police jeep is following him, which is sighted by thief in his rear view mirror, which is a convex mirror of focal length 10 m. He observes that the image of jeep is moving towards him with a velocity of 1 cm//s . if the magnification of mirror for the jeep at that time is 1/10 . Find the actual speed of jeep, Assume the police's jeep is on the axis of the mirror.

    Two roads OA and OB intersect at an angle 60^(@) . A car driver approaches O from A, where OA = 800 metres, at a uniform speed of 20 m/sec. Simultaneasly, O runner starts running from O towards B at uniform speed of 5 m/sec. Find the time when the car and the runner are closest.

    Two blocks of mass m_(1)=10kg and m_(2)=5kg connected to each other by a massless inextensible string of length 0.3m are placed along a diameter of the turntable. The coefficient of friction between the table and m_(1) is 0.5 while there is no friction between m_(2) and the table. the table is rotating with an angular velocity of 10rad//s . about a vertical axis passing through its center O . the masses are placed along the diameter of the table on either side of the center O such that the mass m_(1) is at a distance of 0.124m from O . the masses are observed to be at a rest with respect to an observed on the tuntable (g=9.8m//s^(2)) . (a) Calculate the friction on m_(1) (b) What should be the minimum angular speed of the turntable so that the masses will slip from this position? (c ) How should the masses be placed with the string remaining taut so that there is no friction on m_(1) .

    One hard and stormy night you find yourself lost in the forest when you come upon a small hut. Entering it you see a crooked old woman in the corner hunched over a crystal ball. You are about to make a hasty exit when you hear the howl of wolves outside. Taking another look at the gyspy you decide to take your chances with the wolves, but the door is jammed shut. Resigned to a bad situation you approach her slowly, wondering just what is the focal length of that nifty crystal ball. If the crystal ball is 20 cm in diameter with R.I = 1.5 , the gypsy lady is 1.2m from the ball , where is the image of the gypsy in focus as you walk towards her?

    When an object moves through a fluid, as when a ball falls through air or a glass sphere falls through water te fluid exerts a viscous foce F on the object this force tends to slow the object for a small sphere of radius r moving is given by stoke's law, F_(w)=6pietarv . in this formula eta in the coefficient of viscosity of the fluid which is the proportionality constant that determines how much tangential force is required to move a fluid layer at a constant speed v, when the layer has an area A and is located a perpendicular distance z from and immobile surface. the magnitude of the force is given by F=etaAv//z . For a viscous fluid to move from location 2 to location 1 along 2 must exceed that at location 1, poiseuilles's law given the volumes flow rate Q that results from such a pressure difference P_(2)-P_(1) . The flow rate of expressed by the formula Q=(piR^(4)(P_(2)-P_(1)))/(8etaL) poiseuille's law remains valid as long as the fluid flow is laminar. For a sfficiently high speed however the flow becomes turbulent flow is laminar as long as the reynolds number is less than approximately 2000. This number is given by the formula R_(e)=(2overline(v)rhoR)/(eta) In which overline(v) is the average speed rho is the density eta is the coefficient of viscosity of the fluid and R is the radius of the pipe. Take the density of water to be rho=1000kg//m^(3) Q. Blood vessel is 0.10 m in length and has a radius of 1.5xx10^(-2) m blood flows at rate of 10^(-7)m^(3)//s through this vessel. The pressure difference that must be maintained in this flow between the two ends of the vessel is 20 Pa what is the viscosity sufficient of blood?

    When an object moves through a fluid, as when a ball falls through air or a glass sphere falls through water te fluid exerts a viscous foce F on the object this force tends to slow the object for a small sphere of radius r moving is given by stoke's law, F_(w)=6pietarv . in this formula eta in the coefficient of viscosity of the fluid which is the proportionality constant that determines how much tangential force is required to move a fluid layer at a constant speed v, when the layer has an area A and is located a perpendicular distance z from and immobile surface. the magnitude of the force is given by F=etaAv//z . For a viscous fluid to move from location 2 to location 1 along 2 must exceed that at location 1, poiseuilles's law given the volumes flow rate Q that results from such a pressure difference P_(2)-P_(1) . The flow rate of expressed by the formula Q=(piR^(4)(P_(2)-P_(1)))/(8etaL) poiseuille's law remains valid as long as the fluid flow is laminar. For a sfficiently high speed however the flow becomes turbulent flow is laminar as long as the reynolds number is less than approximately 2000. This number is given by the formula R_(e)=(2overline(v)rhoR)/(eta) In which overline(v) is the average speed rho is the density eta is the coefficient of viscosity of the fluid and R is the radius of the pipe. Take the density of water to be rho=1000kg//m^(3) Q. If the sphere in previous question has mass of 1xx10^(-5)kg what is its terminal velocity when falling through water? (eta=1xx10^(-3)Pa-s)

    Home
    Profile