Exam 4: The Laws of Motion

Only two forces act on a 3.0-kg mass.One of the forces is 9.0 N east,and the other is 8.0 N in the direction of 62 $\degree$ north of west.What is the magnitude of the acceleration of the mass?

The figure shows a uniform,horizontal beam (length = 10 m,mass = 25 kg)that is pivoted at the wall,with its far end supported by a cable that makes an angle of 51 $\degree$ with the horizontal.If a person (mass = 60 kg)stands 3.0 m from the pivot,what is the tension in the cable?

A 5.0-kg object is suspended by a string from the ceiling of an elevator that is accelerating downward at a rate of 2.6 m/s².What is the tension in the string?

A block is pushed up a frictionless 30 $\degree$ incline by an applied force as shown.If F = 25 N and M = 3.0 kg,what is the magnitude of the resulting acceleration of the block?

A 2.0-kg object has a velocity of 4.0 î m/s at t = 0.A constant resultant force of (2.0 î0 + 4.0 ĵ )N then acts on the object for 3.0 s.What is the magnitude of the object's velocity at the end of the 3.0-s interval?

Given the equation $( 3.00 \mathrm {~kg} ) \left( 5.88 \frac { \mathrm { m } } { \mathrm { s } ^ { 2 } } \right) = ( 3.00 \mathrm {~kg} ) \left( 9.80 \frac { \mathrm { m } } { \mathrm { s } ^ { 2 } } \right) - ( 2.00 \mathrm {~kg} ) \left( 5.88 \frac { \mathrm { m } } { \mathrm { s } ^ { 2 } } \right)$ ,which answer provides the best description of a possible physical situation?

The horizontal surface on which the objects slide is frictionless.If F = 12 N,what is the tension in string 1?

If M = 6.0 kg,what is the tension in string 1?

If M = 1.1 kg,what is the tension in string 1?

An object of unknown weight is suspended as shown.The tension in rope 1 is 25 lb,and the tension in rope 2 is 31 lb.What is the weight of the suspended object?

A 25-ft long crane supported at its lower end by a pin is elevated by a horizontal cable as shown in the figure.A 250-lb load is suspended from the outer end of the crane.The center of gravity of the crane is 10 ft from the pin,and the crane weighs 200 lb.What is the tension in the horizontal cable?

A book is placed on a chair.Then a videocassette is placed on the book.The floor exerts a normal force

If $\alpha$ = 40 $\degree$ and the tension in string 2 is 30 N,determine M.

The tension in a string from which a 4.0-kg object is suspended in an elevator is equal to 44 N.What is the acceleration of the elevator?

A 3.0-kg block slides on a frictionless 20 $\degree$ inclined plane.A force of 16 N acting parallel to the incline and up the incline is applied to the block.What is the acceleration of the block?

The horizontal surface on which the objects slide is frictionless.If M = 2.0 kg,the tension in string 1 is 12 N.Determine F.

Exhibit 5-2 A 4.00 kg block is suspended from the roof of an elevator.A 2.00 kg block is suspended from the 4.00 kg block.The tensions in strings 1 and 2 are labeled $\vec { T } _ { 1 }$ and $\vec { T } _ { 2 }$ Use this exhibit to answer the following question(s). -Refer to Exhibit 5-2.When the elevator accelerates downwards with an acceleration of 2.20 m/s²,the magnitudes of $\vec { T } _ { 1 }$ and $\vec { T } _ { 2 }$ are

A person weighing 0.70 kN rides in an elevator that has an upward acceleration of 1.5 m/s².What is the magnitude of the force of the elevator floor on the person?

When the vector sum of three co-planar forces, $\overrightarrow { \mathrm { A } }$ , $\vec { B }$ and $\overrightarrow { \mathrm { C } }$ ,is parallel to $\overrightarrow { \mathrm { A } }$ ,we can conclude that $\vec { B }$ and $\overrightarrow { \mathrm { C } }$

A high-diver of mass 70.0 kg jumps off a board 10.0 m above the water.If,two seconds after entering the water,his downward motion is stopped,what average upward force did the water exert on him?