Physics 6

A sign with a mass of m is hung symmetrically from two cables which make an angle of theta with the horizontal (see diagram). The tension in each one of the cables is Ftens. The vertical component of the tension force is Fy; the horizontal component is Fx. Which of the following mathematical statements are true? (Statements are comparing the magnitudes only; not the directions.) 2 diagonal strings, arrow pointing down for gravity

-Fgrav = Fy + Fy -Fy = 0.5 • m • g

A sign is hung symmetrically from two cables that make an angle with the horizontal (see diagram). The sign is in a state of static equilibrium. Which of the following statements are true? 2 diagonal lines

-The net force on the sign is zero. -The horizontal component of force in one cable balances the horizontal component of force in the other cable. -The vector sum of all the forces is zero. -Gravity does NOT exert a horizontal force component on the sign.

If an object is at equilibrium, then which of the following MUST be true?

-The velocity (whether zero or non-zero) is constant. -The acceleration is 0 m/s/s. -The forces are balanced. -The net force is 0 N.

Which of the following descriptions COULD be true of an object that is at equilibrium?

-the object is at rest. -the object is moving -the object is moving with a constant velocity.

A sign is hung by two cables; each makes an angle of theta with the horizontal. As the angle theta is DECREASED, the weight of the sign ___ ; the tension force in the cable ___, and the vertical component of the tension force ___

Remains the same, increases, remains the same

Vector A is resolved into two components - Ax and Ay. If the two components are added together in head-to-tail fashion, then the resultant would ____.

be the original vector A

A box of mass 'm' is being dragged across a rough, level surface having a coefficient of friction of 'mu.' A force is being applied to the box in an upward and a rightward direction (as shown below). This force makes an angle of 30 degrees with the horizontal. The force of friction experienced by the box would be equal to ____. up arrow, left arrow, down arrow larger than left and up, diagonal arrow up and right.

c. mu • ( m • g - Fapp • sin (30 degrees) ) f. the coefficient of friction multiplied by the normal force acting upon the box

A box of mass 'm' is being dragged across a rough, level surface having a coefficient of friction of 'mu.' A force is being applied to the box in an upward and a rightward direction (as shown below). This force makes an angle of 30 degrees with the horizontal. The force of friction experienced by the box would be equal to ____.

d. ... nonsense! None of these would be equal to the force of friction on the box.

A box is being accelerated across a level surface. A force is being applied to the box in an upward and a rightward direction (as shown below). This force makes an angle of 30 degrees with the horizontal. If the angle at which the force is exerted is increased to 45 degrees, then the normal force would ____.

decrease

Vector components are important in physics because they describe the ____.

effect of a vector in a given direction

A box is being accelerated across a level surface. A force is being applied to the box in a downward and rightward direction (as shown below). In this situation, the normal force is ____ the force of gravity.

greater than

Vector components might be best defined as the ____.

projection of a vector onto an axis