A man walks 3.55 km north and then 2.75 km east, all in 2.60 hours.
(a)
What is the magnitude (in km) and direction (in degrees north of east) of his displacement during the given time?
magnitude km direction ° north of east
(b)
What is the magnitude (in km/h) and direction (in degrees north of east) of his average velocity during the given time?
magnitude km/h direction ° north of east
(c)
What was his average speed (in km/h) during the same time interval?
km/h
2.
[–/3 Points]
SerCP11 3.1.P.001.
An airplane in a holding pattern flies at constant altitude along a circular path of radius 3.62 km. If the airplane rounds half the circle in 130 s, determine the following.
(a)
Determine the magnitude of the airplane’s displacement during the given time (in m).
m
(b)
Determine the magnitude of the airplane’s average velocity during the given time (in m/s).
m/s
(c)
What is the airplane’s average speed during the same time interval (in m/s)?
m/s
3.
[–/2 Points]
SerCP11 3.2.OP.008.
A baseball pitcher throws a ball at 94.0 mi/h in the horizontal direction. How far does the ball fall vertically by the time it reaches home plate, which is a horizontal distance of 60.5 ft away? (Express your answer in units of feet. Neglect air resistance.)
ft
4.
[–/2 Points]
SerCP11 3.2.OP.009.
A mountain lion jumps to a height of 2.80 m when leaving the ground at an angle of 43.8°. What is its initial speed (in m/s) as it leaves the ground?
m/s
5.
[–/1 Points]
SerCP11 3.2.OP.013.
A rock is tossed from the top of a building at an angle of 35° above the horizontal with an initial speed of 13 m/s. The rock lands on the ground 3.1 s after it is tossed. What is the height of the building (in m)?
m
6.
[–/4 Points]
SerCP11 3.2.OP.015.
In a stunt filmed for a movie, a truck rolls down an incline and off a vertical cliff, falling into a river below. The truck starts from rest and rolls down the incline, which makes an angle of 22.0° below the horizontal, with a constant acceleration of 3.52 m/s2. After rolling down the incline a distance of 30.0 m, it reaches the edge of the cliff, which is 50.0 m above the river.
(a)
How much time (in s) does it take the truck to fall from the edge of the cliff to the landing point?
s
(b)
At the point where the truck lands in the river, how far is it horizontally from the edge of the cliff (in m)?
m
7.
[–/2 Points]
SerCP11 3.2.OP.018.
Water from a fire hose is directed toward a building as shown in the figure below. The water leaves the hose at a speed of
vi = 40.0 m/s
and at an angle of
𝜃i = 44.0°
above the horizontal. The base of the hose (at ground level) is a horizontal distance
d = 49.0 m
away from the building. Find the height h (in m) where the water strikes the building.
A fireman on the ground sprays water from a fire hose onto a building. The water leaves the hose with velocity vector vi at an acute angle 𝜃i above the horizontal and curves downwards just before it strikes the building at a height h above the ground. The building is a horizontal distance d from the fireman.
m
8.
[–/2 Points]
SerCP11 3.2.P.011.MI.
A place-kicker must kick a football from a point 36.0 m (about 40 yards) from the goal. Half the crowd hopes the ball will clear the crossbar, which is 3.05 m high. When kicked, the ball leaves the ground with a speed of 21.4 m/s at an angle of 51.0° to the horizontal.
(a) By how much does the ball clear or fall short (vertically) of clearing the crossbar? (Enter a negative answer if it falls short.)
m
(b) Does the ball approach the crossbar (and cross above or beneath it) while still rising or while falling?
rising falling
9.
[–/2 Points]
SerCP11 3.2.P.016.
An artillery shell is fired with an initial velocity of 300 m/s at 46.0° above the horizontal. To clear an avalanche, it explodes on a mountainside 50.0 s after firing. What are the x- and y-coordinates of the shell where it explodes, relative to its firing point?
x =
m
y =
m
10.
[–/2 Points]
SerCP11 3.3.P.021.
Suppose a boat moves at 10.2 m/s relative to the water. If the boat is in a river with the current directed east at 1.50 m/s, what is the boat’s speed relative to the ground when it is heading east, with the current, and west, against the current? (Enter your answers in m/s.)
(a)
east with the current
m/s
(b)
west against the current
m/s
11.
[–/3 Points]
SerCP11 3.2.P.012.
The record distance in the sport of throwing cowpats is 81.1 m. This record toss was set by Steve Urner of the United States in 1981. Assuming the initial launch angle was 45° and neglecting air resistance, answer the following.
(a) Determine the initial speed of the projectile.
m/s
(b) Determine the total time the projectile was in flight.
s
(c) Qualitatively, how would the answers change if the launch angle were greater than 45°? Explain.
This answer has not been graded yet.
12.
[–/4 Points]
SerCP11 3.3.P.022.MI.
A car travels due east with a speed of 58.0 km/h. Raindrops are falling at a constant speed vertically with respect to the Earth. The traces of the rain on the side windows of the car make an angle of 50.0° with the vertical. Find the velocity of the rain with respect to the car and the earth. (Enter the magnitude of the velocity.)
(a) the car
km/h
(b) the Earth
km/h
13.
[–/4 Points]
SerCP11 3.3.P.026.
An airplane maintains a speed of 591 km/h relative to the air it is flying through as it makes a trip to a city 773 km away to the north. (Assume north is the positive y-direction and east is the positive x-direction.)
(a) What time interval is required for the trip if the plane flies through a headwind blowing at 34.8 km/h toward the south?
h
(b) What time interval is required if there is a tailwind with the same speed?
h
(c) What time interval is required if there is a crosswind blowing at 34.8 km/h to the east relative to the ground?
h
14.
[–/6 Points]
SerCP11 3.A.P.039.
A rocket is launched at an angle of 53.0° above the horizontal with an initial speed of 97 m/s. The rocket moves for 3.00 s along its initial line of motion with an acceleration of 29.0 m/s2. At this time, its engines fail and the rocket proceeds to move as a projectile.
(a) Find the maximum altitude reached by the rocket.
m
(b) Find its total time of flight.
s
(c) Find its horizontal range.
m
15.
[–/3 Points]
SerCP11 3.A.P.044.
A 2.00-m-tall basketball player is standing on the floor 10.0 m from the basket, as in the figure below. If he shoots the ball at a 40.0° angle with the horizontal, at what initial speed must he throw the basketball so that it goes through the hoop without striking the backboard? The height of the basket is 3.05 m.
m/s
A basketball player attempting a three point shot is shown. The player is standing 10.0 m away from the basket. The height at which he releases the ball is 2.00 m. The angle is shown at the point where the ball is released and is 40.0° above the horizontal. The path of the ball from the player to the basket is shown as a parabolic arc ending at the basket, which is at a height of 3.05 m.
16.
[–/3 Points]
SerCP11 3.A.P.049.
A hunter wishes to cross a river that is 2.3 km wide and flows with a speed of 5.0 km/h parallel to its banks. The hunter uses a small powerboat that moves at a maximum speed of 10 km/h with respect to the water. What is the minimum time necessary for crossing?
min
17.
[–/2 Points]
SerCP11 3.A.P.052.
If raindrops are falling vertically at 8.50 m/s, what angle from the vertical do they make for a person jogging at 2.39 m/s? (Enter your answer in degrees.)
The post A man walks 3.55 km north and then 2.75 km east, all appeared first on PapersSpot.