Exam 3: Motion in Two and Three Dimensions

Mark throws a ball to Daniel with an initial speed of 20 m/s at an angle of 45 degrees.If they are initially 55 m apart,calculate the average speed Daniel has to run to catch the ball.(Assume the ball is thrown and caught at the same height.Also assume that Daniel starts to run when the ball is thrown.)

If an object is moving west,its acceleration

A car is at position (x₁,y₁)= (4 m,5 m)at time t₁ = 1 s.If 10 seconds later the car moving in a straight line is at position (x₂,y₂)= (204 m,305 m),calculate the distance traveled by the car in this interval.

A vector has an x component of -5.51 units and a y component of +9.52 units.The angle between the positive direction of the vector and the positive direction of the x axis is

If you ignore air resistance in projectile motion,the ________ of the projectile remains constant.

The initial position and velocity of a projectile are given by and respectively,and where r is in m and v in m/s.The position in the vertical direction (in m)as a function of time is

The initial position and velocity of a projectile are given by and respectively,and where r is in m and v in m/s.The position in the horizontal direction (in m)as a function of time is

A projectile is ejected from a 25-m high tower with a velocity of 40 m/s at an angle of 30 degrees to the horizontal first on Earth and then on Mars.What is the ratio of the time taken to hit the ground on Mars compared to Earth? (Assume g_Mars = 0.38g_Earth)

Use the diagram to answer the question. The curve shows the position of an object with time.The object moves with a constant speed,v. -Which of the vector diagrams below best represent the change in velocity vector from P₁ to P₂?

The position vector of an object is given by and 4 s later,its position vector is .The units are in m.The magnitude of the change in the position vector is

A pilot wants the heading of an airplane to be 45º east of north.The wind is from 270º at 32 km/h,and the speed of the airplane through the air is 320 km/h.The pilot should maintain a heading of approximately

The position vector locating the point P(12,-5)relative to the origin is

Use the following to answer the question: -The figure represents the parabolic trajectory of a ball going from A to E in Earth gravity but without air resistance.At point C the velocity of the ball is

If a baseball is thrown at an angle of elevation of 30º,its range in the absence of air resistance is less than that of one thrown at

A plane is flying horizontally at a height of 500 m and a constant speed of 429 km/h when an object is projected vertically downward at an initial speed of 35.0 m/s.If air resistance is neglected,the average vertical component of velocity between the object's release and its striking the ground is

A train,starting from rest,accelerates along the platform at a uniform rate of 0.6 m/s².A passenger standing on the platform is 5 m away from the door when the train starts to pull away and heads toward the door at an acceleration of 1.2 m/s².How long does it take the passenger to reach the door?

Use the diagram to answer the question. The curve shows the position of an object with time.The object moves with a constant speed,v. -Which of the vector diagrams below best represent the velocity vector at P₁ and P₂?

The position vector of an object is given by and 4 s later,its position vector is .The units are in m.The change in the position vector ,in m,is

A particle has an initial velocity of 4.8 m/s toward the south and a final velocity of 7.1 m/s toward the east.The particle was subject to a constant acceleration for 0.25 s.The magnitude and the direction of the acceleration must have been

The figure shows the position of a ball as it is being whirled in a vertical circle. At point (a),the direction of the resultant acceleration (centripetal and tangential)is