Advertisements
Advertisements
Question
If a particle is accelerating, it is either speeding up or speeding down. Do you agree with this statement?
Solution
Acceleration does not mean speeding up or speeding down. It means the change of velocity either in direction or in magnitude.
APPEARS IN
RELATED QUESTIONS
Read the statement below carefully and state, with reason and example, if it is true or false:
A particle in one-dimensional motion with constant speed must have zero acceleration.
On a long horizontally moving belt (Fig. 3.26), a child runs to and fro with a speed 9 km h–1 (with respect to the belt) between his father and mother located 50 m apart on the moving belt. The belt moves with a speed of 4 km h–1. For an observer on a stationary platform outside, what is the
(a) speed of the child running in the direction of motion of the belt ?.
(b) speed of the child running opposite to the direction of motion of the belt ?
(c) time taken by the child in (a) and (b) ?
Which of the answers alter if motion is viewed by one of the parents?
Give example where the velocity of a particle is zero but its acceleration is not zero.
Give example where the velocity is opposite in direction to the acceleration.
Give example where the velocity is perpendicular to the acceleration.
In figure shows the x coordinate of a particle as a function of time. Find the sings of vx and ax at t = t1, t = t2 and t = t3.
A stone is released from an elevator going up with an acceleration a. The acceleration of the stone after the release is
An object having a velocity 4.0 m/s is accelerated at the rate of 1.2 m/s2 for 5.0 s. Find the distance travelled during the period of acceleration.
The displacement of particle is given by x = `2/lambda (1 - e^(-lambdat))`, the acceleration of particle at 2s when λ = 2s–1 will be (Take `l`n 0.018 = – 4)
If the velocity of a car is given by V = (150 − 10x)½ m/s. If a car retards their motion by applying brakes then what will be the acceleration?
A lift is coming from 8th floor and is just about to reach 4th floor. Taking ground floor as origin and positive direction upwards for all quantities, which one of the following is correct?
A graph of x versus t is shown in figure. Choose correct alternatives from below.
- The particle was released from rest at t = 0.
- At B, the acceleration a > 0.
- At C, the velocity and the acceleration vanish.
- Average velocity for the motion between A and D is positive.
- The speed at D exceeds that at E.
Give example of a motion where x > 0, v < 0, a > 0 at a particular instant.
