midterm
An object travels along a straight line across a horizontal surface, and its motion is described by the velocity versus time graph shown in the figure. Which of the following methods will determine the total displacement of the object between 0 s0 s and 5 s5 s? Select two answers.
Finding the area bound by the horizontal axis and the curve from 0 s0 s to 5 s5 s D Using Average Speed=total distancetotalAverage Speed=total distancetotal and multiplying the average speed of 5 ms5 ms by a total time of 5 s
An object is sliding to the right along a straight line on a horizontal surface. The graph shows the object's velocity as a function of time. What is the object's displacement during the time depicted in the graph?
0 m
An object is dropped from the top of a building near Earth's surface. After 2 s2 s, a second identical object is dropped from the same building from the same height. After 4 s4 s, the first object strikes the ground. The graph shows the speeds νν of both objects as a function of time tt. What is the approximate acceleration of the center of mass of the two-object system at the moment right before the first object reaches the ground?
10m/2^2
A 2 kg2 kg object is a distance of 10,000,000 m10,000,000 m away from the center of Earth, which has a mass of nearly 6×1024 kg6×1024 kg. What is the approximate gravitational field strength of Earth's gravitational field at the location of the 10 kg10 kg object?
4 N/kg
A car goes from rest to 30 m/s in 12 s with constant acceleration. How long does it take the car to go from rest to 15 m/s with the same acceleration?
6.0s
An object is thrown with a horizontal velocity of 20 m/s from a cliff that is 125 m above level ground. If air resistance is negligible, the time that it takes the object to fall to the ground from the cliff is most nearly
5 s
Object 1 and object 2 travel across a horizontal surface, and their horizontal velocity as a function of time is shown in the graph. Which of the following statements is correct about the two-object system?
After 2s2s, object 1 travels a greater distance than object 2 travels.
The motion of a particle along a straight line is represented by the position versus time graph above. At which of the labeled points on the graph is the magnitude of the acceleration of the particle greatest?
C
The graph above shows the speed of a truck as it moves along a straight, level road. Which of the following describe a method to determine the distance d the truck travels during the 10 s time interval shown? Select two answers.
Multiply the average speed of 18 m/s by the 10 s travel time. Calculate the area under the line in the graph.
The figure above shows the position of a moon that orbits a planet in an elliptical path. Two specific locations of the moon, position AA and position BB, are labeled. As the moon orbits the planet from position AA to position BB, is the magnitude of the planet's force due to gravity exerted on the moon constant? Why or why not?
No, because the moon's distance from the planet is always changing.
An object travels down a ramp at a constant acceleration. The object experiences a force of friction and a gravitational force. Which of the following could be true about the motion of the object?
The force of friction between the surface and the object is less than the component of the gravitational force that is parallel to the ramp.
The graphs above represent the position x, velocity v, and acceleration a as a function of time t for a marble moving in one dimension. Which of the following could describe the motion of the marble?
Rolling up a ramp and then rolling back down
An object's velocity v as a function of time t is given in the graph above. Which of the following statements is true about the motion of the object?An object's velocity v as a function of time t is given in the graph above. Which of the following statements is true about the motion of the object?
The object's initial and final positions are the same.
A student sets an object attached to a spring into oscillatory motion and uses a motion detector to record the velocity of the object as a function of time. A portion of the recorded data is shown in the figure above. The acceleration of the object at time t = 0.7 s is most nearly equal to which of the following?
The slope of the tangent to a best-fit sinusoidal curve at 0.7 s
A student drops a rock from the top of a cliff such that the rock falls downward toward Earth's surface in the absence of air resistance. The downward direction is considered to be the positive direction. The graph shows the rock's velocity as a function of time. Which of the following methods should be used to determine the total distance traveled by the rock after 4s4s ?
Use the area under the curve, as it states that the rock traveled 8080 meters in total.
A person driving a car suddenly applies the brakes. The car takes 4 s to come to rest while traveling 20 m at constant acceleration. Can the speed of the car immediately before the brakes were applied be determined without first determining the car's acceleration?
Yes, by determining the average speed while braking and doubling it.
Balls 1 and 2 are each thrown horizontally from the same height above level ground, but ball 2 has a greater initial velocity after leaving the thrower's hand. If air resistance is negligible, how do the accelerations of the balls and the times it takes them to hit the ground compare?
a= equal, time to hit ground=equal
An object is thrown with an initial speed v near the surface of Earth. Assume that air resistance is negligible and the gravitational field is constant. An object is thrown with an initial speed u near the surface of Earth. Assume that air resistance is negligible and the gravitational field is constant. If the object is thrown horizontally, the direction and magnitude of its acceleration while it is in the air is
downward and constant
An object is thrown with an initial speed v near the surface of Earth. Assume that air resistance is negligible and the gravitational field is constant. If the object is thrown vertically upward, the direction and magnitude of its acceleration while it is in the air is
downward and constant
A solid metal ball and a hollow plastic ball of the same external radius are released from rest in a large vacuum chamber. When each has fallen 1 m, they both have the same
speed
An object of mass m is initially at rest and free to move without friction in any direction in the xy-plane. A constant net force of magnitude F directed in the +x direction acts on the object for 1 s. Immediately thereafter a constant net force of the same magnitude F directed in the +y direction acts on the object for 1 s. After this, no forces act on the object. Which of the following vectors could represent the velocity of the object at the end of 3 s, assuming the scales on the x and y axes are equal?
yk, linear and like yk yk yk up and yk like ummm its like smack dab middle