Engineering Physics- Chapter 4
22.6 degrees; 13.0m
a vector A has components Ax= 12.0m and Ay=5.00m. a) what is the angle that vector A makes with the +x-axis? b) what is the magnitude of vector A?
a) x=5.5cm; y=0cm b) x=-6.5cm; y=3.8cm c) x=-1cm; y=3.8cm d) 3.9cm; 75 degrees above the - x-axis
Displacement vector A is 5.5 cm long and points along the +x-axis. Displacement vector B is 7.5 cm long and points at +30 degrees to the -x-axis. a) determine the x and y components of vector A. b) determine the x and y components of vector B. c) determine the x and y components of the resultant of these two vectors. d) determine the magnitude and direction of the resultant of these two vectors.
they will hit at the same time
In an air-free chamber, a pebble is thrown horizontally, and at the same instant a second pebble is dropped from the same height. Compare the times of fall of the tow pebbles.
13
The components of vectors A and B are given as follows: Ax= 7.6 B=-5.1 Ay=-9.2 B=-6.8 What is the magnitude of the vector difference B-A?
42m/s; 31 degrees north of west
a velocity vector has components 36m/s westward and 22 m/s northward. What are the magnitude and direction of this vector?
18.1m/s
a boy jumps with a velocity of magnitude 20.0m/s at an angle of 25.0 degrees above the horizontal. What is the horizontal component of boy's velocity?
directly over the package
a pilot drops a package from a plane flying horizontally at a constant speed. neglecting air resistance, when the package hits the ground the horizontal location of the plane will be
24.2m
a player throws a football 50.0 m at 61.0 degrees north of west. what is the westward component of the displacement of the football?
always zero
for general projectile motion with no air resistance, the horizontal component of a projectile's acceleration
remains a non zero constant
for general projectile motion with no air resistance, the horizontal component of a projectile's velocity
d
if A+B=C and their magnitudes are given by A+B=C, then the vectors A and B are oriented a) antiparallel to each other (in opposite directions). b) it is impossible to know from the given info. c) perpendicular relative to one another. d) parallel to each other (in the same direction).
b
if A-B=0, then the vectors A and B have equal magnitudes and are directed in the same direction. a) false b) true
false
if a vector pointing upward has a positive magnitude, a vector pointing downward has a negative magnitude. a) false b) true
c
james and john dive from an overhang into the lake below. james simply drops straight down form the edge. john takes a running start and jumps with an initial horizontal velocity of 25m/s. if there is no air resistance, when they reach the lake below a) the splashdown speed of john must be 25m/s larger than that of james. b) they will both have the same splashdown speed. c) the spalshdown speed of john is larger than that of james. d) the splashdown speed of james is larger than that of john. e) the splashdown sped of james must be 9.8m/s larger than that of john
a,d
mary and debra stand on a snow-covered roof. they both throw snowballs with the same initial speed, but in different directions. mary throws her snowball downward, at 30 degrees blow the horizontal; debra throws her snowball upward, at 30 degrees above the horizontal. which of the following statements are true about just as the snowballs reach the ground below? a) both snowballs will hit the ground with the same speed. b) both snowballs hit the ground at the same time. c) debra's snowball will have a higher speed than mary's snowball d) mary's snowball reaches the ground before debra's snowball. e) mary's snowball will have a higher speed than debra's snowball.
11 units
the x component of vector A is 8.7 units, and its y component is -6.5 units. the magnitude of A is closest to
6.6lb; 68 degrees clockwise from rope A
three ropes are tied in a knot. One student pulls on rope A with 1.0 pound of force, and another student pulls on rope B with 7.0 pounds of force. How hard and in what direction must you pull on rope C to balance the first two pulls? Give the direction by specifying the angle (clockwise or counterclockwise) of the pull with the direction of rope A.
2-12m
two displacement vectors have magnitudes of 5.0m and 7.0m, respectively. if these two vectors are added together, the magnitude of the sum is
increase by a factor of 2
two perpendicular vectors, A and B, are added together giving vector C. the magnitude of vector C will
4.8m/s
when jeff ran up a hill at 7.0m/s, the horizontal component of his velocity vector was 5.1m/s. What was the vertical component of jeff's velocity?
68m
you walk 33m to the north, then turn 60 degrees to your right and walk another 45m. How far are you from where you originally started?
