Exam 2: Motion, Forces, and Newtons Laws

If we know an object is moving at constant velocity, we may assume:

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?

A thrown stone hits a window but doesn't break it. Instead, it reverses direction and ends up on the ground below the window. In this case, we know:

In which of the following cases is the displacement's magnitude half the distance traveled?

A runner circles a track of radius 100 m in 100 s moving at a constant rate. If the runner was initially moving east, what has been the runner's average acceleration when halfway around the track?

A bird, accelerating from rest at a constant rate, experiences a displacement of 37 m in 11 s. What is the final velocity after 11 s?

A jogger runs halfway around a circular path with a radius of 70 m. What, respectively, are the magnitude of the displacement and the distance jogged?

A strobe photograph of a car moving along a straight road shows the interval between each successive image to be diminishing. If the direction of motion of the car is taken as positive, which of the following are negative?

A physics student is riding on a train traveling north. Having read about inertia, the student performs an experiment with a golf ball. He reaches over the aisle and drops the ball from rest. Instead of hitting the floor directly below the student's hand, it hits to the north, i.e., forward of that position. Which of the following might be the cause for this to happen?

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?

Which formula is dimensionally consistent with an expression yielding a value for velocity? (a is acceleration, x is distance, and t is time)

An object, initially moving in the negative x direction, is subjected to a change in velocity in the negative y direction. If the resulting velocity vector is drawn from the origin, into which quadrant does this vector point?

A ball is thrown vertically upwards at 9.8 m/s. For its complete trip (up and back down to the starting position), its average velocity is:

An astronaut applies a force of 500 N to an asteroid, and it accelerates at 3.00 m/s². What is the asteroid's mass?

A car is initially moving at 30 m/s east and a little while later it is moving at 10 m/s north. Which of the following best describes the orientation of the average acceleration during this time interval?

A bird, accelerating from rest at a constant rate, experiences a displacement of 37 m in 11 s. What is the average velocity?

Jeff throws a ball straight up. For which situation is the vertical velocity zero?

A railroad train travels forward along a straight track at 80.0 m/s for 1000 m and then travels at 40.0 m/s for the next 1000 m. What is the average velocity?

Displacement is which of the following types of quantities?

When NASA was communicating with astronauts on the Moon, the time from sending on the Earth to receiving on the moon was 1.33 s. Find the distance from Earth to the Moon. (The speed of radio waves is 3.00 * 10⁸ m/s.)