All angles are measured as anti-clockwise rotations from the +x-axis. An object has an initial velocity of 2.91 m/s at 26.6 degrees. 6.6 seconds later it is moving at 91.15 m/s at an angle of 131.5 degrees. What acceleration caused this change in velocity? (Give your answer in terms of the +x-axis, in degrees)
Acceleration =
,
Angle =
from the positive x axis.

Let f(x) = x4- 8x2 . find the relativeextrema of this function using the second derivative test.

An engineer designs a roller coaster so that a car travels horizontally for 152 ft, then climbs 137 ft at an angle of 34.0° above the horizontal. it then moves 137 ft at an angle of 48.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)

Avoltaic cell converts chemical energy to