Exam 4: Motion in Two and Three Dimensions

An object, tied to a string, moves in a circle at constant speed on a horizontal surface as shown.The direction of the displacement of this object, as it travels from W to X is:

A dart is thrown horizontally toward X at 20 m/s as shown.It hits Y 0.1 s later.The distance XY is:

A large cannon is fired from ground level over level ground at an angle of 30° above the horizontal.The muzzle speed is 980 m/s.Neglecting air resistance, the projectile will travel what horizontal distance before striking the ground?

Which of the following is a vector quantity?

A bullet shot horizontally from a gun:

Which of the following is NOT an example of accelerated motion?

Which of the following is a scalar quantity?

A Ferris wheel with a radius of 8.0m makes 1 revolution every 10 s.When he is at the top, essentially a diameter above the ground, he releases a ball.How far from the point on the ground directly under the release point does the ball land?

For a biological sample in a 1.0-m radius centrifuge to have a centripetal acceleration of 25g its speed must be:

A stone is thrown horizontally and follows the path XYZ shown.The direction of the acceleration of the stone at point Y is:

The velocity of an object as a function of time is given by v = (12.5t − 7.2t²) + (4.3t³) .What is its acceleration as a function of time?

An airplane makes a gradual 90°turn while flying at a constant speed of 200 m/s.The process takes 20.0 seconds to complete.For this turn the magnitude of the average acceleration of the plane is:

A girl jogs around a horizontal circle with a constant speed.She travels one fourth of a revolution, a distance of 25 m along the circumference of the circle, in 5.0 s.The magnitude of her acceleration is:

An object moves from x = -2.1 m, y = 3.7 m to x = 3.3 m, y = -1.1 m in a time of 5.3 s.What is its average velocity?

An airplane is flying north at 500 km/h.It makes a gradual 180° turn at constant speed, changing its direction of travel from north through east to south.The process takes 40 s.The average acceleration of the plane for this turn is:

An object is shot from the back of a railroad flatcar moving at 40 km/h on a straight horizontal road.The launcher is aimed upward, perpendicular to the bed of the flatcar.The object falls:

Sally starts from home, walks 300 m east and then 500 m south, and arrives at her school.How far, in a straight line, is Sally's school from her home?

A ball is thrown horizontally from the top of a 20-m high hill.It strikes the ground at an angle of 45°.With what speed was it thrown? Use g = 10 m/s².

An object is moving on a circular path of radius $\pi$ meters at a constant speed of 4.0 m/s.The time required for one revolution is:

Velocity is defined as: