Home
Class 11
PHYSICS
A pebble of mass 0.05 kg is thrown verti...

A pebble of mass 0.05 kg is thrown vertically upwards Give the magnitude and direction of net force on the pebble (a) during its upward motion (b) during its downward motion (c) at the highest point where it is momentarily rest
Do your answers change if the pebble were thrown at an angle of say `45^(@)` horizontal direction lgnore air resistance .

Text Solution

Verified by Experts

Whenever a body is thrown vertically upwards or it moves vertically downwards
As `m = 0.05 kg and a = + 10 m//s^(2)`
`:.` In all the three cases `F = ma = 0. 05 xx 10 = 0.5 N` vertically downwards
If the pebble were thrown at an angle of `45^(@)` with the horizontal direction it will have horizontal and vertical components of velocity These components do not affect the force on the pebble . Hence our answers do not alter in any case However in case (c) the pebble will not be at rest It will have horizontal component of velocity at the highest point .
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • LAWS OF MOTION

    PRADEEP|Exercise Additional Examples / Exercises|6 Videos

  • LAWS OF MOTION

    PRADEEP|Exercise Short Answer Questions|35 Videos

  • LAWS OF MOTION

    PRADEEP|Exercise Advanced problems for competitions|20 Videos

  • KINEMATICS

    PRADEEP|Exercise 1 NCERT Comprehension|4 Videos

  • MATHEMATICAL TOOLS

    PRADEEP|Exercise Fill in the blanks|5 Videos

Similar Questions

Explore conceptually related problems

Find the magnitude and direction of the force acting on the particle of mass m during its motion in the plane xy according to the law x=a sin omega t , y=b cos omega t , where a, b, and omega are constants.

A stone is thrown in a vertically upward direction with a velocity of 5ms-1.If the acceleration of the stone during its motion is 10ms-2 in the downward direction,what will be the height attained by the stone and how much time will it take to reach there?

Knowledge Check

  • A stone of mass 0.05 kg is thrown vertically upwards. What is the direction and magnitude of net force on the stone during its upward motion?

    A
    0.98 N vertically downwards
    B
    0.49 N vertically downwards
    C
    9.8 N vertically downwards
    D
    0.49 N vertically upwards

  • For a body thrown vertically upwards, its direction of motion changes at the point where its total mechanical energy is

    A
    greater than the potential energy
    B
    less than the potential energy
    C
    equal to the potential energy
    D
    zero

  • A stone is thrown in a vertically upward direction with a velocity of 5 m//s . If the acceleration of the stone during its motion is 10 m//s^(2) in the downward direction, what will be the height attained by the stone and how much time will take to reach there ?

    A
    2 m , 20 sec
    B
    1.25 m , 0.5 sec
    C
    12.5 m , 5 sec
    D
    20 m, 2 sec

    • Similar Questions

    Explore conceptually related problems

    A player throws a ball upwards with an initail speed of 129.4 ms^(-1) (a) What is the direction of acceleration during the upward motion of the ball ? (b) What are the velocity and accleration of the ball at the ighest point os its motion. ( c) Choose the =x 0 aand t= 0 be the loction and time at its highest point, vertically downward direction to be the positve direction of X-axis and give the signe of position, velocity and accelration of the ball during its upward, and downward motion. (d) To what hight does the ball rise and after how long does the ball returns to the plausr s hands. (Take g= 9.8 ms^(-23) and begleact air resistance)

    A player throwsa a ball upwards with an initial speed of 29.4 ms^(-1) . (i) What is the direction of acceleration during the upwared motion of the ball? (ii) What are the velocity and acceleration of the ball at the highest point of its motion? (iii) Choose the x=0 and t=0 to be the location and time of the ball at its highest point, vertically downward direction to be the positive direction of X-axis, and give the signs of positive, velocity and acceleration of the ball during its upward, and downward motion. (iv) To what height does the ball rise and after how long does the ball return to the player's hand?( Take g =9.8 ms^(-2) , and neglect air resistance).

    A ball of mass 0.2 kg thrown vertically upwards with a velcity of 30 m/s, reaces the highest point in 2.5 second. What is the air resistance experienced by the ball during its vertical motion? [g=10m//s^(2)]

    When a particle is undergoing motion, the diplacement of the particle has a magnitude that is equal to or smaller than the total distance travelled by the particle. In many cases the displacement of the particle may actually be zero, while the distance travelled by it is non-zero. Both these quantities, however depend on the frame of reference in which motion of the particle is being observed. Consider a particle which is projected in the earth's gravitational field, close to its surface, with a speed of 100sqrt(2) m//s , at an angle of 45^(@) with the horizontal in the eastward direction. Ignore air resistance and assume that the acceleration due to gravity is 10 m//s^(2) . Consider an observer in frame D (of the previous question), who observes a body of mass 10 kg acelerating in the upward direction at 30 m//s^(2) (w.r.t. himself). The net force acting on this body, as observed from the ground is :-

    When a particle is undergoing motion, the diplacement of the particle has a magnitude that is equal to or smaller than the total distance travelled by the particle. In many cases the displacement of the particle may actually be zero, while the distance travelled by it is non-zero. Both these quantities, however depend on the frame of reference in which motion of the particle is being observed. Consider a particle which is projected in the earth's gravitational field, close to its surface, with a speed of 100sqrt(2) m//s , at an angle of 45^(@) with the horizontal in the eastward direction. Ignore air resistance and assume that the acceleration due to gravity is 10 m//s^(2) . " A third observer (C) close to the surface of the reports that particle is initially travelling at a speed of 100sqrt(2) m//s making on angle of 45^(@) with the horizontal, but its horizontal motion is northward". The third observer is moving in :-

    Home
    Profile