A large crate of mass m is placed on the back of a truck but not tied down. As the truck accelerates forward with an acceleration a, the crate remains at rest relative to the truck. What force causes the crate to accelerate forward? (a) the normal force (b) the force of gravity (c) the force of friction between the crate and the floor of the truck (d) the “ma” force (e) none of these

A 71-kg woman holds a 9-kg package as she stands within an elevator which briefly accelerates upward at a rate of 0.19g. Determine the force R which the elevator floor exerts on her feet and the lifting force L which she exerts on the package during the acceleration interval. If the elevator support cables suddenly and completely fail, what values would R and Lacquire? Answers: 9kg 71kg H *** While accelerating, 0.19g R= i After the cables fail, R = i N L = i N L = i N N

A block of mass m1 rests on horizontal ground. A block of mass m2 rests on m1. There is no friction between m1 and the ground. There is friction only between m2 and m1. A horizontal force of magnitude F is then applied to m1   Consider the statments: I) the friction force on m2 is to the right. II) suppose that F is small enough for the two blocks to move with the same acceleration a>0. In this case, the friction force is static. III) suppose that F is large enough for the two blocks to move with different accelerations. In this case, the acceleration of m2 relative to the ground is to the left.   Which of them are true?

One 3.6-kgkg paint bucket is hanging by a massless cord from another 3.6-kgkg paint bucket, also hanging by a massless cord.  a) If the two buckets are pulled upward with an acceleration of 1.25 m/s^2 by the upper cord, calculate the tension in the top cord. b) If the two buckets are pulled upward with an acceleration of 1.25 m/s^2 by the upper cord, calculate the tension in the bottom cord.

A 32.7-kg crate rests on a horizontal floor, and a 62.0-kg person is standing on the crate. Determine the magnitude of the normal force that (a) the floor exerts on the crate and (b) the crate exerts on the person.

The 1 kg standard body has an acceleration of 2.00 m/s2 at 41° to the positive direction of the x axis. (a) What are the x and y components of the net force on it? x component      N y component      N (b) What is the net force in unit-vector notation? =         N

Two forces F, and F2 act on a 5.40-kg object. F1 = 25.0 N and F2 = 13.0 N. a (a) Find the acceleration of the object for the configuration of forces shown in Figure (a). magnitude m/s2 direction ° (counterclockwise from F,) (b) Find the acceleration of the object for the configuration of forces shown in Figure (b). magnitude m/s? direction ° (counterclockwise from F,)

If a man weighs 850N on the Earth, what would he weigh on Jupiter, where the free-fall acceleration is 25.9 m/s2? A 00-kg object undergoes an acceleration given by = (4.00 î + 9.00 ĵ) m/s2.  Find the resultant force and its magnitude acting on the object.

An SUV containing 5 passengers has a mass of 3500 kg. It has a driving force of 2500 N directed west on a perfectly horizontal road. The surface of the road exerts a resistive force of 500 N due east. At the same time, a strong wind is blowing a force of 500 N due east in the opposite direction of the car's drive force. Does the car have any acceleration? If yes, then what is the magnitude and direction of the car's acceleration?

The 1 kg standard body has an acceleration of 2.00 m/s² at 63° to the positive direction of the x axis. (e) What are the x and y components of the net force on it? x component N y component (b) What is the net force in unit-vector notation? F