- #1
ncr7
- 41
- 0
The velocity of a particle moving in the xy plane is given by = (5.6 t - 4.5 t2) + 8.2, with in meters per second and t (> 0) in seconds. (a) What is the acceleration when t = 3.3 s? (b) When (if ever) is the acceleration zero? (c) When (if ever) does the speed equal 10 m/s?
I got the first 2 but when I went to find c I can't seem to get it.
I took
10m/s = sqrt((5.6t - 4.5t^2)^2 + (8.2)^2
10^2 = (sqrt((5.6t - 4.5t^2)^2 + (8.2)^2)^2
100 = (5.6t - 4.5t^2)^2 + 67.24)
32.76 = (5.6t - 4.5t^2)^2
sqrt(32.76) = sqrt((5.6t - 4.5t^2)^2)
5.72 = 5.6t - 4.5t^2
0 = -4.5t^2 + 5.6t - 5.72
then I used quadratic to find out the two values...
but I get a negative in the sqrt on the quadratic and I can't do that... any suggestions?
I got the first 2 but when I went to find c I can't seem to get it.
I took
10m/s = sqrt((5.6t - 4.5t^2)^2 + (8.2)^2
10^2 = (sqrt((5.6t - 4.5t^2)^2 + (8.2)^2)^2
100 = (5.6t - 4.5t^2)^2 + 67.24)
32.76 = (5.6t - 4.5t^2)^2
sqrt(32.76) = sqrt((5.6t - 4.5t^2)^2)
5.72 = 5.6t - 4.5t^2
0 = -4.5t^2 + 5.6t - 5.72
then I used quadratic to find out the two values...
but I get a negative in the sqrt on the quadratic and I can't do that... any suggestions?