Advertisements
Advertisements
प्रश्न
Give the magnitude and direction of the net force acting on a drop of rain falling down with a constant speed.
Advertisements
उत्तर
Since the raindrop falls downward at a constant velocity, its acceleration is zero. Therefore, according to Newton's first law of motion, the net force acting on the raindrop is zero, i.e., a = 0 Consequently, from the equation F = ma, we have F = 0.
APPEARS IN
संबंधित प्रश्न
If the speed of the stone is increased beyond the maximum permissible value, and the string breaks suddenly, which of the following correctly describes the trajectory of the stone after the string breaks?
A moving bicycle comes to rest after sometime if we stop pedalling it. But Newton’s first law of motion says that a moving body should continue to move for ever, unless some external force acts on it. How do you explain the bicycle case ?
Define one newton force.
Find the acceleration produced by a force of 5 N acting on a mass of 10 kg.
Is it possible for a particle to describe a curved path if no force acts on it? Does your answer depend on the frame of reference chosen to view the particle?
It is sometimes heard that the inertial frame of reference is only an ideal concept and no such inertial frame actually exists. Comment.
A plumb bob is hung from the ceiling of a train compartment. If the train moves with an acceleration 'a' along a straight horizontal track , the string supporting the bob makes an angle tan−1 (a/g) with the normal to the ceiling. Suppose the train moves on an inclined straight track with uniform velocity. If the angle of incline is tan−1 (a/g), the string again makes the same angle with the normal to the ceiling. Can a person sitting inside the compartment tell by looking at the plumb line whether the train is accelerating on a horizontal straight track or moving on an incline? If yes, how? If not, then suggest a method to do so.
A force F1 acts on a particle accelerating it from rest to a velocity v. Force F1 is then replaced by F2 which decelerates the particle to rest.
In an imaginary atmosphere, the air exerts a small force F on any particle in the direction of the particle's motion. A particle of mass m projected upward takes time t1 in reaching the maximum height and t2 in the return journey to the original point. Then.
A particle stays at rest as seen in a frame. We can conclude that
(a) the frame is inertial
(b) resultant force on the particle is zero
(c) the frame may be inertial but the resultant force on the particle is zero
(d) the frame may be non-inertial but there is a non-zero resultant force
'When a hanging carpet is beaten with a stick, the dust particles start coming out of it'. This phenomenon can be best explained by making use of :
State and explain the law of inertia (or Newton's first law of motion).
Give qualitative definition of force on the basic of Newton's first law of motion.
A car of mass m starts from rest and acquires a velocity along east `v = vhati (v > 0)` in two seconds. Assuming the car moves with uniform acceleration, the force exerted on the car is ______.
In the above given problem if the lower thread is pulled with a jerk, what happens?
Block A of weight 100 N rests on a frictionless inclined plane of slope angle 30° (figure). A flexible cord attached to A passes over a frictonless pulley and is connected to block B of weight W. Find the weight W for which the system is in equilibrium.

A force F is applied to the initially stationary cart. The variation of force with time is shown in the figure. The speed of the cart at t = 5 sec is ______.
Match the following.
| Column I | Column II |
| a. Newton’s I law | propulsion of a rocket |
| b. Newton’s II law | Stable equilibrium of the body |
| c. Newton’s III law | Law of force |
| d. Law of conservation of Linear momentum | Flying nature of bird |
If the net force on an object is zero, what happens?
