Unlock document.
This document is partially blurred.
Unlock all pages and 1 million more documents.
Get Access
PROBLEM 11.192
The end Point B of a boom is originally 5 m from fixed Point A
when the driver starts to retract the boom with a constant radial
acceleration of 2
1.0 m/sr
and lower it with a constant
angular acceleration 2
0.5 rad/s .
At 2 s,t determine
(a) the velocity of Point B, (b) the acceleration of Point B,
(c) the radius of curvature of the path.
SOLUTION
22 2 2
( 2) ( 3) 3.6055 m/s
r
vvv
PROBLEM 11.192 (Continued)
Direction of velocity.
r
ee
v
4.7149 m/s
n
a
PROBLEM 11.193
A telemetry system is used to quantify
kinematic values of a ski jumper
immediately before she leaves the ramp.
According to the system 500 ft,r
105 ft/s,r
2
10 ft/s ,r
25 ,
0.07 rad/s,
2
0.06 rad/s .
Determine
(a) the velocity of the skier immediately
before she leaves the jump, (b) the
acceleration of the skier at this instant,
(c) the distance of the jump d neglecting lift
and air resistance.
SOLUTION
PROBLEM 11.193 (Continued)
(c) Distance of the jump d.
PROBLEM 11.193 (Continued)
PROBLEM 11.CQ1
A bus travels the 100 miles between A and B at 50 mi/h and then another 100
miles between B and C at 70 mi/h. The average speed of the bus for the
entire 200-mile trip is:
(a) more than 60 mi/h
(b) equal to 60 mi/h
(c) less than 60 mi/h
SOLUTION
PROBLEM 11CQ2
Two cars A and B race each other down a straight
road. The position of each car as a function of time
is shown. Which of the following statements are
true (more than one answer can be correct)?
(a) At time t2 both cars have traveled the same
distance
(b) At time t1 both cars have the same speed
(c) Both cars have the same speed at some time t < t1
(d) Both cars have the same acceleration at some
time t < t1
(e) Both cars have the same acceleration at some
time t1 < t < t2
PROBLEM 11.CQ3
Two model rockets are fired simultaneously from a ledge and follow
the trajectories shown. Neglecting air resistance, which of the rockets
will hit the ground first?
(a) A
(b) B
(c) They hit at the same time.
(d) The answer depends on h.
PROBLEM 11.CQ4
Ball A is thrown straight up. Which of the following statements about the ball are true at the
highest point in its path?
(a) The velocity and acceleration are both zero.
(b) The velocity is zero, but the acceleration is not zero.
(c) The velocity is not zero, but the acceleration is zero.
(d) Neither the velocity nor the acceleration are zero.
PROBLEM 11.CQ5
Ball A is thrown straight up with an initial speed v0 and reaches a maximum elevation h before falling back
down. When A reaches its maximum elevation, a second ball is thrown straight upward with the same initial
speed v0. At what height, y, will the balls cross paths?
(a) y h
(b) y h/2
(c) y h/2
(d) y h/2
(e) y 0
PROBLEM 11.CQ6
Two cars are approaching an intersection at constant speeds as shown. What velocity will
car B appear to have to an observer in car A?
(a) (b) (c) (d) (e)
/BABA
PROBLEM 11.CQ7
Blocks A and B are released from rest in the positions shown. Neglecting friction between all surfaces, which
figure below best indicates the direction
of the acceleration of block B?
PROBLEM 11.CQ8
The Ferris wheel is rotating with a constant angular velocity
. What is
the direction of the acceleration of Point A?
(a)
(b)
(c)
(d)
(e) The acceleration is zero.
PROBLEM 11.CQ9
A racecar travels around the track shown at a constant speed. At
which point will the racecar have the largest acceleration?
(a) A
(b) B
(c) C
(d) The acceleration will be zero at all the points.
PROBLEM 11.CQ10
A child walks across merry-go-round A with a constant speed u relative to
A. The merry-go-round undergoes fixed axis rotation about its center with a
constant angular velocity counterclockwise.When the child is at the
center of A, as shown, what is the direction of his acceleration when viewed
from above.
(a)
(b)
(c)
(d)
(e) The acceleration is zero.
SOLUTION
