9. You are pushing a 30-kg wooden crate across the floor. The force of sliding friction
on the crate is 90 N. How much force must
you exert on the crate to keep it moving
with a constant velocity?

In which of the following cases is work being done on an object? question 2 options: pulling a trailer up a hill carrying a box down a corridor suspending a heavy weight with a strong chain pushing against a locked door

Frank just graduated from eighth grade. assuming exactly four years from now he will graduate from high school how many seconds does he have until his high school graduation

The vector a? is 3.50 cm long and is directed into this page. vector b? points from the lower-right corner of this page to the upper-left corner of this page and has the components bx=-19.5 cm , by=25 cm. in the right-handed coordinate system, where the +x-axis directed to the right, the +y-axis toward the top of the page, and +z-axis out of the page, find the x-component of the vector product a? ×b? , measured in cm2.