If Luis pulls straight down on the end of a wrench that is tilted θ = 30∘ above the horizontal and is r = 37 cm long, what force must he apply to exert a torque of -21 N⋅m ?

The equation that relates force and torque is Torque = Force*length*sin(angle). Plug in the given values to the equation (convert length to meters first): -13 = Force * 0.35 * sin(30 degrees). Rearrange to solve for Force: Force = -13/(0.35 * 0.5) = -74.3 N (which is the same as a downward force of magnitude 74.3 N.

The correct choice is c

Answertraveling around a circular trackexplanation"traveling around a circular track" is the best answer as you could be traveling around a circular track at a constant speed. your velocity would therefore have the same magnitude but will always be constantly direction. since acceleration is the rate of change of velocity, the rate of change will only involve the direction of velocity and not the magnitude.wrong choices: "an object at rest" does not accelerate at all"increasing speed while traveling around a curve" means that the acceleration will not be constant due to only change in direction; it will be constant due to both magnitude and direction"an object in free fall" does not necessarily change direction