Question
Physics Question on Motion in a straight line
Figure 2.13 gives the x-t plot of a particle executing one-dimensional simple harmonic motion. (You will learn about this motion in more detail in Chapter13). Give the signs of position, velocity and acceleration variables of the particle at t= 0.3s,1.2s,–1.2s.
Negative, Negative, Positive (at t = 0.3s)
Positive, Positive, Negative (at t = 1.2s)
Negative, Positive, Positive (at t = −1.2s)
For simple harmonic motion (SHM) of a particle, acceleration (a) is given by the relation:
a =–ω2×ω→angularfrequency ....(i)
t = 0.3s
In this time interval, x is negative. Thus, the slope of the x - t plot will also be negative.Therefore, both position and velocity are negative. However, using equation (i), acceleration of the particle will be positive.
t = 1.2s
In this time interval, x is positive. Thus, the slope of the x - t plot will also be positive. Therefore, both position and velocity are positive. However, using equation (i) acceleration of the particle comes to be negative.
t = –1.2s
In this time interval, x is negative. Thus, the slope of the x - t plot will also be negative. Since both x and t are negative, the velocity comes to be positive. From equation (i), it can be inferred that the acceleration of the particle will be positive.