Question
I need some help in this
A block weighing 77.5 N rests on a plane inclined a t 25.0 degree to the horizontal. A force F is applied to the object at 40.0 degree to the horizontal, pushing it upward on the plane. The coefficients of static and kinetic friction between the block and the plane are, respectively , 0.339 and 0.156. What is the minimum value of F that will prevent the block from slipping down the plane? What is the minimum value of F that will prevent the block from moving down the plane? What value of F will move the block up the plane with constant velocity? If the coefficient of static friction between your coffee cup and the horizontal dashboard of your car is mu s = 0.660, how fast can you drive on a horizontal roadway around a right turn of radius 26.5 m before the cup starts to slide? I f you go too fast, in what direction will the cup slide relative to the dashboard? to the right to the left to the front to the back Vector A rightarrow has a magnitude of 4.95 units, and vector B rightarrow has a magnitude of 8.64 units. The two vectors make an angle of 52.0 degree with each other. Find A rightarrow middot B rightarrow. A force F rightarrow = (8 i^ - 3 i^) N acts on a particle that undergoes a displacement delta r rightarrow = (4 i^ + j^)m. Find the work done by the force on the particle. (Calculate all numerical answers to three significant figures.) What is the angle between F rightarrow and Delta r rightarrow? For and find A particle is subject to a force Fx that varies with position as shown in the following figure. Find the work done by the force on the particle as it moves from x = 0 to x = 4.00 m. Find the work done by the force on the particle as it moves from x = 5.00 m to x = 7.00 m. Find the work done by the force on the particle as it moves from x = 10.0 m to x = 15.0 m. What is the total work done by the force over the distance x = 0 to x = 15.0 m? An archer pulls her bowstring back 0.396 m by exerting a force that increases uniformly from zero to 215 N. What is the equivalent spring constant of the bow? How much work does the archer do on the string in drawing the bow? In 1990 Walter Arfeuille of Belgium lifted a 281.5-kg object through a distance of 17.1 cm using only his teeth. How much work was done on the object by Arfeuille in this lift, assuming the object was lifted at constant velocity ? What total force was exerted on Arfeuille's teeth during the lift?
Explanation / Answer
3)A.B=mod(A)mod(B)*cos(52)=20.74
5)A-B=(5i+j-2k)-(-2i+j+3k)=7i-5k
C.(A-B)=(5j-3k).(7i-5k)=15
6)area occupied by the line to x-axis=work done by the force on particle
a)area=4*2.5=10
work done by the force on particle=5N
b)work done by the force on particle=2*3=6N
c)work done by the force on particle=5*3/2=7.5N
d)work done by the force on particle=sum of works=7.5+15+7.5=30N