The position vector of a particle →R as a function of time is given by →R=4sin(2πt)^i+4cos(2πt)^j Where R is in meters, t is in seconds and ^i and ^j denote unit vectors along x and y-directions, respectively. Which one of the following statements is wrong for the motion of particle?
The correct option is(D)
Given,
Position vector →R=4sin(2πt)→i+4cos(2πt)→j
For finding the velocity vector we have to differentiate it with respect to the time
So,
dRdt=→v=8πcos(2πt)→i−8πsin(2πt)→j
For finding the acceleration we have to differentiate the velocity with respect to the time
So,
dvdt=→a=−4(2π)2sin(2π)→i−4(2π)2cos(2πt)→j=−(2π)2→R
So we can say that the acceleration is in the direction of −−→−R
Now we have to find the magnitude of the velocity
Magnitude of the velocity = √(8πcos(2πt))2−(8πsin(2πt))2
After solving this we get
The magnitude of the velocity = 8π
Now,
Magnitude of the acceleration = ∣∣∣−(2π)2→R∣∣∣=16π2=(8π)24=v2R
Hence from all the above findings, we can say that the only option (D) is wrong