07.10: Contact forces are e.-m8bbxbub cpu(2g3 o xamples of which of the fundamental forces?

  99.02: Which of the uk h yeo-l:r1t:cqc7 )following terms is NOT related conceptually to the others?

  02.20: The graph shows the relx.9r8fawi q l(gyrpr u j.o4l5/,c6zsationship between the mass of a number of rubber stoppers and their resulting weight on some far-off planet. The slope of the graph is a representation of thez y fg9os.8 urr./li,alr q65cw(j x4p:

  10.15: Three blocks, labeled A,B, and C, remain at rest on awp.;xmrpu p,lo o18pc:enw- 9 table. The magnitude of the gravitational force on each block is indicated on the figure. What is the magnitude 1emo:rxl - ; 8 nwu,op.p9wcppof the contact force on block C from block B?

  14.04: Three equal masses are susptrk/1n rt6;d.v8hhn a ended from a classroom ceiling by a series of strings as shown in the figure. Which strnah kt6 ./nr;rtd1hv8ing has the greatest tension?

  16.05: In the figure shown,n q 4z4at61 -jl7zfhzs the mass m = 6.0 k。and the mass M = 14.0 k。are stationary. The mass M rests on the floor. Which one of the following choices represents the tension in the string connal1hj q fnz-zt467z 4secting the masses?

  14.13: Which one of the following scientists is most associatewtz-- n fo tx3qqqh4(6d with the following statement: “For small displacements of an object from equilibrium, there is a restoring force6fzqt(o- q4w- hx tn3q that is proportional to the displacement.”?

  94.26: As shown in the accompanying figure, a force F is exer qpxp3-xqyg/lw*c *gpk 92+rwted at an angle of y-kwx /r2q wl9*qx +ggppc3*p$\theta$. The block of weight mg is initially moving the right with speed $v$. The coefficient of friction between the rough floor and the block is $\mu$. The frictional force acting on the block is:

  95.34: A student pullexv-cq6me tq0k/w56 j s a wooden box along a rough horizontal floor at constant speed by q6jc5mq /0-xwevte6k means of a force P as shown to the right. Which of the following must be true?

  99.08: A weight can be hung in any oft*bp gu 4nmg 1hm; r6byse2kqt(.(q6k the following four ways. In which case is the string most likely togkup;1 h(gs.t*6 myrmqn24bqk6be (t break?

  96.39: Assume the objects in the following diagrams have equabt2pqy t7dbt4 8e x*aws/e*s6 l mass and the strings holding them in place are ident*ey* s78w t/bdtes46 tab2q pxical. In which case would the string be most likely to break?

  16.10: A person wishes to accelerate an object upward uniformly. Whce 9i 4 uugh7nwo02e2fich one of the following choices must be true of the force F, provided by the person onto the ouu7 wce024en2 o9gfih bject? W represents the magnitude of the gravitational force acting on the object. Ignore any effects of the air or of the Earth’srotation.

  11.12: A 5.0 kg mass moves along th/ka0v)g 4y,ame1+ea wwti k f.e x-axis, at one instant of time, the mass has position 2.0 m, veloc+vk)fwmawe4, 1 a ykt/ agi.e0ity 3.0 m/s,and acceleration $4.0\;m/s^{2}$ . What is the net force acting on the mass at this instant of time?

  11.15: A 4.0 kg object is pushed 65zd-sw+m r7gqx mu iez0-gg(to the right on a rough surface by a horizontal force of 15 N as shown, during the push, the object accelerates unifor+gg7x 6s5 q-ezmidm z(u0r-gwmly to the right at 2.5 $m/s^{2}$ . What must be the magnitude of the force of friction also acting on the object during the push?

  96.32: The 10.0 kg box shown in m4wp1f14hlni2w whthcy/e(- the figure to the right is sliding to the right along the floor. A horizontal force of 10.0 N is being applied to the right. The coefficient of kinetic fr1n-ew myc4lp/ h 4ww2 iht1(hfiction between the box and the floor is 0.20. The box is moving with:

  00.32: A block rests on a flat plane incliwphr /ddrsgz-) a k+;2ned at an angle of $30^{\circ}$ with respect to the horizontal. What is the minimum coefficient of friction necessary to keep the block from sliding?

  99.32: A wooden box is first pulled across a horizontal steel plate y jp6a f9j(iidv7,n1l as shown in the diagram li6vfa7pd9n(jy1 j ,iA.
The box is then pulled across the same steel plate while the plate is inclined as shown in diagram B. How does the force required to overcome friction in the inclined
case (B) compare to the horizontal case (A)?

  07.09: A block rests on an incf ll7i1x678n zehs8 ii;e:x mcline that makes the angle θ with the horizontal. The block remains at rest as θ is slowly increased. The magnitudes of the normal force and the static frictional force of the incline s7zn6e8 x;:mi 8el cfxhi71 ilon the block

  01.11: A 5 kg block rests on a flat plane inclineptrcj )a o(3l4d at an angle of $30^{\circ}$ to the horizon as shown in the diagram below.

What would be the acceleration of the block down the plane assuming the force of friction is negligible?

  01.12: If the block ipoenack)z1( qpc oj*qw+4cc( 227si ys placed on a second plane (where friction is significant) in inclined at the same a42inpj+q2c 7c(o s1z ecw(kq a*pc o)yngle, it will begin to accelerate at 2.0 m/s. What is the force of friction between the block and the second inclined plane?

  08.08: An object on an inclined plane has a gravitation0o:2sdnch 5uxal force of magnitude N 10 acting on it from the Earth. Which of the following gives the correct components of this gravitational force for the coordinate axes shown in the figure? The y-axis is perpendicular to the incline’s surface while the x-axis is pa205cnhx ud :osrallel to the inclined surface.

  15.13: An object is being pushed at constant speed on an inclined plane. ;qvqif(ze+-3ujl r3 *gmkl *yThe free body diagram of the object is shown with the gravitational force represented by W, the friction force by f, the applied external push parallel to the incline by F, and the normal force with the surface by n. Which one of the following choices rq3*g+(*vjrl m ql-f3e;iuy zkepresents correct relationships between

  08.20: A person pushes a block of mass M=6.0 kg with a cat,9uqma *yq(onstant speed of 5.0 m/s straight up a q( at,9*u mqyaflat surface inclined $30^{\circ}$above the horizontal. The coefficient of kinetic friction between the block and the surface is μ = 0.40. What is the net force acting on the block?

  14.20: A uniform block of mass misplaced on an inclined plane of angle θ ,t (3hmxpke dl (je4 tv8/nf7z. When released, the block does not move. It is determined that f3etp/le7z kt4 ,( hvjdxn( 8mthe normal force acting from the incline on the block has a magnitude of 62 N while the force of static friction acting on the block has a magnitude of 38 N. The coefficient of static friction between the block and inclined plane is 0.92. Which one of the following choices best represents the mass,m, of the block?

  17.40: A small object of mass M is released from rest at the top of a frictionlec i*v;k8 aek *h7z/sfass incline. The inclinehas a mass M and makes an angle θ with the horizontal. The incline remains at reston a table as c*7eskhk /8; f*azvai thesmall object slides. During the slide, what is the magnitude of the normal force from the table on the incline?