Determine the minimum initial velocity $V_0$ and the corresponding angle ${}_0$ at which the ball mus

be kicked in order for it to iust cross over the $3-$m high fence.

The jet plane is traveling with a speed of $120\frac{m}{s}$ which is decreasing at $40\frac{m}{s^2}$ when it reaches

point $A.$ Determine the magnitude of its acceleration when it is at this point. Also, specify the

direction of flight, measured from the $x-$axis.

The motor draws in the cable at $C$ with a constant velocity of $v_c=4\frac{m}{s}.$ The motor draws in the

cable at $D$ with a constant acceleration of $a_D=8\frac{m}{s^2}.$ If $v_D=0$ when $t=0,$ determine $($a$)$ the tim

needed for block $A$ to rise $3$ m $,$ and $($b$)$ the relative velocity of block A with respect to block $B$

when this occurs.

Two planes, A and $B,$ are flying at the same altitude. If their velocities are $v_A=500k\frac{m}{h}$ and $v_B=$

$700k\frac{m}{h}$ such that the angle between their straight$-$line courses is $=60,$ determine the velocity

of plane $B$ with respect to plane $A.$

The $10-lb$ block has a speed of $4f\frac{t}{s}$ when the force of $F=(8t^2)lb$ is applied. Determine the

velocity of the block when it moves $s=30ft.$ The coefficient of kinetic friction at the surface is ${}_s$

$=0\mathrm{.}2.$

The $0\mathrm{.}8-Mg$ car travels over the hill having the shape of a parabola. When the car is at point $A,$ it

is traveling at $9\frac{m}{s}$ and increasing its speed at $3\frac{m}{s^2}.$ Determine both the resultant normal forc

and the resultant frictional force that all the wheels of the car exert on the road at this instant

Neglect the size of the car.

The force F$,$ acting in a constant direction on the $20-kg$ block, has a magnitude which varies with

the position $s$ of the block. Determine how far the block must slide before its velocity becomes $15$

$\frac{m}{s}.$ When $s=0$ the block is moving to the right at $v=6\frac{m}{s}.$ The coefficient of kinetic friction

between the block and surface is ${}_k=0\mathrm{.}3.$

The elevator $E$ and its freight have a total mass of $400$ kg $.$ Hoisting is provided by the motor $M$

and the $60-kg$ block $C.$ If the motor has an efficiency of $=0\mathrm{.}6,$ determine the power that must be

supplied to the motor when the elevator is hoisted upward at a constant speed of $v_E=4\frac{m}{s}.$