At t = 0,a particle leaves the origin with a velocity of 12 m/s in the positive x direction and moves in the xy plane with a constant acceleration of
)At the instant the y coordinate of the particle is 18 m,what is the x coordinate of the particle?
A)30 m
B)21 m
C)27 m
D)24 m
E)45 m

Question

At t = 0,a particle leaves the origin with a velocity of 12 m/s in the positive x direction and moves in the xy plane with a constant acceleration of 
)At the instant the y coordinate of the particle is 18 m,what is the x coordinate of the particle?
A)30 m 
B)21 m 
C)27 m 
D)24 m 
E)45 m

Quizplus · Accepted Answer

We can use the kinematic equation,
y = yo +voyt + 1/2 ayt^2
Here, y=18m, yo=0, voy=0 (as there is no initial velocity in y direction), a=constant=-11ea7ff9_2a5b_1d6d_a768_a3bbe4e4c1aa_TB2295_11 and t is the time taken to reach y=18m in y-direction.
Solving for time taken to reach y=18 m we get, t = sqrt(36/11) seconds. 
Now, for finding X, we can use another kinematic equation,
x = xo + vox t + 1/2 axt^2
Here, xo = 0, vox = 12 m/s, a = constant = 0 (as there is no acceleration in x-direction)
Putting values, we get the x-coordinate to be 27 m. Therefore, the answer is (C).

At T = 0,a Particle Leaves the Origin with a Velocity