This problem involves one-dimensional horizontal motion. Don't worry about any vertical forces (like the force of Earth's gravity) in your calculations. I'll say the motion is along the x axis.

The mass of an object is 1.73kg. Its position x as a function of time is given by

x = (3.45 m/s^2)t^2 + (2.22 m/s^5)t^5

Determine the net force (along the x axis) acting on the object at t = 1.33s. Give your answer to at least 3 sig figs.

## Answers (1)

v = dx/dt = 6.90t + 11.1t^4

a = dv/dt = 6.90 + 44.4t^3

F = ma

F = (1.73 kg)[6.90 m/s^2 + (44.4 m/s^5)t^3]

At t = 1.33s,

F = (1.73 kg)[6.90 m/s^2 + (44.4 m/s^5)(1.33 s)^3]

F = 193 N