Physics test 2/3 questions
A startled deer runs 520 m at 20.0° north of east for half a minute, then turns and runs 380 m at 55.0° north of west for 15.0 seconds and stops. What is the average velocity of the deer during this time?
12.4 m/s
A projectile is thrown horizontally at 11.5 m/s. The projectile hits the ground 0.570 s later. What is the angle of impact the projectile makes with the horizontal ground?
-25.9°
A car is initially traveling west at 25 mph, and makes a turn north. As the car finishes the turn, its velocity is 20 mph north. It takes 3.5 seconds to complete the turn. What is the average acceleration of the car while it is turning, in mph/s? Let east be the positive-x direction and north be the positive-y direction.
-7.1 i + 5.7 j
A bird, accelerating from rest at a constant rate, experiences a displacement of 25 m in 12 s. What is its acceleration?
0.35 m/s^2
An object moves 10.0 m east in 10.0 s and then returns to its starting point taking an additional 40.0 s. If west is chosen as the positive direction, what is the average speed of the object?
0.4 m/s
A ball is thrown vertically upwards at 24.5 m/s. For its complete trip (up and back down to the starting position), its average speed is
12.3 m/s
A mouse starts out in a corner of a room, and runs across the floor according to the following displacements: d1: 1.2 m i + 0.4 m j d2: 0.2 m i - 0.8 m j What is the magnitude of the total displacement of the mouse's position?
1.5 m
A baseball is released at rest from the top of the Washington Monument. It hits the ground after falling for 5.85 s. What was the height from which the ball was dropped? (g = 9.80 m/s^2 and assume air resistance is negligible)
1.68 × 10^2 m
A 50.0-g ball traveling at 22.0 m/s is bounced off a brick wall and rebounds at 21.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 2.50 ms, what is the average acceleration of the ball during this time interval?
1.72E+4 m/s^2
A baseball thrown from the outfield is released from shoulder height at an initial velocity of 29.1 m/s at an initial angle of 30.0° with respect to the horizontal. What is the maximum vertical displacement that the ball reaches during its trajectory?
10.8 m
A string attached to an airborne kite is maintained at an angle of 44.0° with the horizontal. If a total of 160 m of string is reeled in while bringing the kite back to the ground, what is the horizontal displacement of the kite in the process? (Assume the kite string doesn't sag.)
115 m
A vehicle designed to operate on a drag strip accelerates from zero to 34 m/s while undergoing a straight-line path displacement of 48 m. What is the vehicle's acceleration if its value may be assumed to be constant?
12 m/s^2
In which of the following cases is the displacement's magnitude half the distance traveled?
12 steps east followed by 4 steps west
A jogger runs halfway around a circular path with a radius of 60.0 m. What, respectively, are the magnitude of the displacement and the distance jogged?
120 m, 188 m
A ball is pushed downhill with an initial velocity of 3.0 m/s. The ball rolls down a hill with a constant acceleration of 1.6 m/s^2. The ball reaches the bottom of the hill in 6.0 s. What is the ball's velocity at the bottom of the hill?
13 m/s
A bridge that was 10.4 m long has been washed out by the rain several days ago. How fast must a car be going to successfully jump the stream, if we neglect air resistance? Although the road is level on both sides of the bridge, the road on the far side is 3.00 m lower than the road on this side.
13.3 m/s
A European sports car dealer claims that his product will accelerate at a constant rate from rest to a speed of 100 km/hr in 8.00 s. What is the speed after the first 4.00 s of acceleration? (Hint: First convert the speed to m/s.)
13.9 m/s
John throws a baseball from the outfield from shoulder height, at an initial velocity of 41.5 m/s at an initial angle of 40.0° with respect to the horizontal. The ball is in its trajectory for a total interval of 5.00 s before the third baseman catches it at an equal shoulder-height level. (Assume air resistance negligible.) What is the ball's horizontal displacement?
159 m
Human reaction time is usually about 0.18 s. If your lab partner holds a ruler between your finger and thumb and releases it without warning, how far can you expect the ruler to fall before you catch it? The nearest value is
16 cm
A ball is pushed with an initial velocity of 4.0 m/s. The ball rolls down a hill with a constant acceleration of 1.7 m/s^2. The ball reaches the bottom of the hill in 7.0 s. What is the ball's velocity at the bottom of the hill?
16 m/s
A water rocket, launched from the ground, rises vertically with acceleration of 25 m/s^2 for 2.0 s when it runs out of "fuel." Disregarding air resistance, how high will the rocket rise?
178 m
A car's initial velocity is 50.0 km/h in the direction 60.0° north of east, and its final velocity is 70.0 km/h in the direction 40.0° south of east. If the time period for this journey is 30.0 minutes, what is the magnitude of the car's average acceleration?
186 km/h/h
An automobile driver puts on the brakes and decelerates from 35.0 m/s to zero in 11.0 s. What distance does the car travel?
193 m
A rock is rolled in the sand. It starts at 5.0 m/s, moves in a straight line for a distance of 6.0 m, and then stops. What is the magnitude of the average acceleration?
2.1 m/s^2
A bird, accelerating from rest at a constant rate, experiences a displacement of 22 m in 10 s. What is the average velocity?
2.2 m/s
A Cessna aircraft has a lift-off speed of 135 km/h. What minimum constant acceleration does this require if the aircraft is to be airborne after a take-off run of 260 m?
2.70 m/s^2
A truck moves 80.0 m east, then moves 140.0 m west, and finally moves east again a distance of 80.0 m. If east is chosen as the positive direction, what is the truck's resultant displacement?
20.0 m
A plane is moving due north, directly towards its destination. Its airspeed is 210 mph. A constant breeze is blowing from west to east at 20.0 mph. At what rate is the plane moving north?
209 mph
John throws a rock down with speed 11 m/s from the top of a 25-m tower. If g = 9.8 m/s^2 and air resistance is negligible, what is the rock's speed just as it hits the ground?
25 m/s
A stone is thrown with an initial speed of 11.5 m/s at an angle of 50.0 above the horizontal from the top of a 30.0-m-tall building. Assume air resistance is negligible, and g = 9.8 m/s^2. What is the magnitude of the vertical-velocity component of the rock as it hits the ground?
25.8 m/s
A stone is thrown with an initial speed of 11.5 m/s at an angle of 50.0 above the horizontal from the top of a 30.0-m-tall building. Assume air resistance is negligible, and g = 9.8 m/s^2. What is the magnitude of the horizontal displacement of the rock?
26.1 m
A fireman, 57.6 m away from a burning building, directs a stream of water from a fire hose at an angle of 35.2° above the horizontal. If the initial speed of the stream is 42.7 m/s, at what height will the stream of water strike the building?
27.3 m
Gwen releases a rock at rest from the top of a 40-m tower. If g = 9.8 m/s^2 and air resistance is negligible, what is the speed of the rock as it hits the ground?
28 m/s
Wiley Coyote has missed the elusive road runner once again. This time, he leaves the edge of the cliff at 52.4 m/s horizontal velocity. If the canyon is 140 m deep, how far from his starting point at the edge of the cliff does the coyote land?
280 m
An object, initially moving in the negative x-direction, is subjected to a change in velocity in the positive y-direction. If the resulting velocity vector is drawn from the origin, into which quadrant does this vector point?
2nd
A speeding car traveling at a constant velocity of v passes a police car initially at rest beside the roadway. If the police car with constant acceleration of a immediately pursues the speeding car, how long is it before the police car is directly behind the speeding car?
2v/a
A bird, accelerating from rest at a constant rate, experiences a displacement of 25 m in 15 s. What is the final velocity after 15 s?
3.3 m/s
A European sports car dealer claims that his car will accelerate at a constant rate from rest to 100 km/h in 8.00 s. If so, what is the acceleration? (Hint: First convert speed to m/s.)
3.47 m/s^2
A rock is thrown straight up with an initial velocity of 25.0 m/s. What maximum height will the rock reach before starting to fall downward? (Take acceleration due to gravity as 9.80 m/s^2.)
31.9 m
A rock, released at rest from the top of a tower, hits the ground after 3.5 s. What is the speed of the rock as it hits the ground? (g = 9.8 m/s^2 and air resistance is negligible)
34 m/s
Plane A is flying at 440 mph in the northeast direction relative to the Earth. Plane B is flying at 550 mph in the north direction relative to the Earth. What is the speed of Plane B as observed from Plane A?
392 mph
A boat travels upstream and after one hour has gone 10 km. The boat next travels downstream and after one hour has gone 18 km. If the boat's speed relative to the water is constant, what is the speed of the current in the river?
4 km/h
Maria throws two stones from the top edge of a building with a speed of 22 m/s. She throws one straight down and the other straight up. The first one hits the street in a time t1. How much later is it before the second stone hits?
4.5 s
Plane A is flying at 350 mph in the northeast direction relative to the Earth. Plane B is flying at 460 mph in the north direction relative to the Earth. What is the direction of motion of Plane B as observed from Plane A?
40.7° N of W
A stone is thrown at an angle of 30° above the horizontal from the top edge of a cliff with an initial speed of 8.0 m/s. A stop watch measures the stone's trajectory time from top of cliff to bottom to be 5.9 s. How far out from the cliff's edge does the stone travel horizontally? (g = 9.8 m/s2 and air resistance is negligible)
41 m
A projectile is fired directly upwards at 49.4 m/s. A second projectile is dropped from rest at some higher elevation at the instant the first projectile is fired and passes the first projectile 3.00 s later. From the frame of reference of the first projectile, what is the velocity of the second projectile as it passes by?
49.4 m/s, downward
A baseball leaves the bat with a speed of 47 m/s and an angle of 45° above the horizontal. A 5.0-m-high fence is located at a horizontal distance of 137 m from the point where the ball is struck. Assuming the ball leaves the bat 1.0 m above ground level, by how much does the ball clear the fence?
49.7 m
A ball is launched from ground level at 25 m/s at an angle of 31° above the horizontal. How far does it go before it is at ground level again?
56 m
A jet airliner moving at 470 mph due east moves into a region where the wind is blowing at 110 mph in a direction 30.0° north of east. What is the new velocity and direction of the aircraft?
568 mph, 5.56° N of E
A plane is moving due north, directly towards its destination. Its airspeed is 210 mph. A constant breeze is blowing from west to east at 25.0 mph. In which direction is the plane pointed?
6.79° W of N
A stone is thrown with an initial speed of 11.5 m/s at an angle of 50.0 above the horizontal from the top of a 30.0-m-tall building. Assume air resistance is negligible, and g = 9.8 m/s^2. What is the magnitude of the horizontal-velocity component of the rock as it hits the ground?
7.39 m/s
A helicopter is traveling at 50.0 m/s at a constant altitude of 150 m over a level field. If a wheel falls off the helicopter, with what speed will it hit the ground? (g = 9.8 m/s^2 and air resistance negligible)
74 m/s
A railroad train travels forward along a straight track at 90.0 m/s for 1000 m and then travels at 70.0 m/s for the next 1000 m. What is the average velocity?
78.8 m/s
A rifle is aimed horizontally toward the center of a target 120 m away. If the bullet strikes 11.2 cm below the center, what was the velocity of the bullet? (Ignore air friction.)
790 m/s
A stone is thrown at an angle of 30° above the horizontal from the top edge of a cliff with an initial speed of 12 m/s. A stop watch measures the stone's trajectory time from top of cliff to bottom to be 4.8 s. What is the height of the cliff? (g = 9.8 m/s^2 and air resistance is negligible)
84 m
A cheetah can run at approximately 100 km/h and a gazelle at 80.0 km/h. If both animals are running at full speed, with the gazelle 50.0 m ahead, how long before the cheetah catches its prey?
9.0 s
A projectile is launched with speed v at an angle θ, the angle being less than 45º. What other angle would give the same range for this projectile launched at the same speed v?
90° - θ
A projectile is fired at an angle of elevation of 30°. Neglecting air resistance, what are possible angles in flight between the acceleration vector and the velocity vector?
90° and 30°
An object moves along the x axis, with its position given by the function x(t) = ½ t^3. Which of the following can be obtained from a graph of x vs. t?
All of the above
Two projectiles are launched at 100 m/s, the angle of elevation for the first being 30° and for the second 60°. Which of the following statements is false?
All of the above statements are true
In one-dimensional motion, the average speed of an object that moves from one place to another and then back to its original place has which of the following properties?
It is positive
A hiker walks 200 m west and then walks 100 m north. In what direction is her resulting displacement?
None of the answers is correct
Two baseballs are released at the same time. One is dropped from rest and the other is given an initial horizontal velocity. Which of the following is not true? Ignore atmospheric drag.
The horizontal component of velocity increases at a greater rate than the vertical component of velocity for both while they are both in the air.
Starting from rest, a car accelerates down a straight road with constant acceleration a for a time t, then the direction of the acceleration is reversed, (i.e., it is −a), and the car comes to a stop in an additional time t, the time for the whole trip being 2t. At what time, or times, is the average velocity of the car for the trip equal to its instantaneous velocity during the trip?
This occurs at 2 times, 0.5t and 1.5t
Starting from rest, a car accelerates down a straight road with constant acceleration a1 for a time t1, then the acceleration is changed to a different constant value a2 for an additional time t2. The total elapsed time is t1 + t2. Can the equations of kinematics be used to find the total distance traveled?
Yes, break the problem up into 2 problems, one with the conditions for the first time interval and the other with the conditions for the second time interval, noting that for the second time interval the initial velocity is that from the end of the first time interval. When done, add the distances from each of the time intervals.
A baseball is thrown by the center fielder (from shoulder level) to home plate where it is caught (on the fly at an equal shoulder level) by the catcher. At what point is the ball's speed at a minimum? (air resistance is negligible)
at the top of the trajectory
A baseball is thrown by the center fielder (from shoulder level) to home plate where it is caught (on the fly at shoulder level) by the catcher. At what point does the magnitude of the vertical component of velocity have its minimum value? (air resistance is negligible)
at the top of the trajectory
Which formula is dimensionally consistent with an expression yielding a value for velocity? (a is acceleration, x is distance, and t is time)
at
On a position-versus-time graph, the slope of the straight line joining two points on the plotted curve that are separated in time by the interval Δt, is which of the following quantities?
average velocity
A car is moving along a straight highway and accelerates at a constant rate while going from point A to point B. If the acceleration is positive, increasing the speed of the car, where does the position where the instantaneous speed equals the average speed occur for the interval from A to B?
closer to A than to B
In a two-dimensional Cartesian system, the x-component of a vector is known, and the angle between vector and x-axis is known. Which operation is used to calculate the magnitude of the vector? (taken with respect to the x-component)
dividing by cosine
A projectile is launched at an angle less than 30° and at speed v. Which will increase the projectile's range more, ignoring atmospheric drag?
increasing the speed of launch by 50%
A plane is moving due north, directly towards its destination. Its airspeed is 220 mph. A constant breeze is blowing from west to east at 50 mph. How long will it take for the plane to travel 220 miles north?
more than one hour
A ball is thrown vertically upwards at 19.0 m/s. For its complete trip (up and back down to the starting position), its average velocity is:
not given
The value of an object's acceleration may be characterized in equivalent words by which of the following?
rate of change of velocity
A strobe photograph shows equally-spaced images of a car moving along a straight road. If the time intervals between images is constant, which of the following cannot be positive?
the acceleration of the car
An x vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the velocity of the ball is zero. We can be positive that at t = 5 s,
the ball has stopped
The slope of the acceleration vs. time curve represents
the rate of change of acceleration
A boat moves through the water in a river at a speed of 8 m/s relative to the water. The boat makes a trip downstream and then makes a return trip upstream to the original starting place. Which trip takes longer?
the upstream trip
Consider the magnitude of the average speed, vavg, speed, mag, and the magnitude of the average velocity, vavg, velocity, mag, for the same trip. Which of the following is always true?
vavg, speed, mag ≥ vavg, velocity, mag
