Forces and Motion in Two Dimensions

Vector A has a magnitudde of 30 units. Vector B is perpendicular to vector A and has a magnitude of 40 units. What would the magnitude of resultant vector A + B be?

• 10 units

• 50 units

• 70 units

• zero

A motoboat heads due east at 5.0 m/s across a river that flow toward the south at a speed of 5.0 m/s.

What is the resultant velocity relative to an observer on the shore?

• 3.2 m/s to the southeast

• 5.0 m/s to the southeast

• 7.1 m/s to the southeast

• 10.0 m/s to the southeast

The pilot of a plane measures an air velocity of 165 km/h south relative to the plane. An observer on the ground sees the plane pass overhead at a velocity of 145 km/h towards to the north. What's the velocity of the wind that is affecting the plane relative to the observer?

• 20 km/h to the north

• 20 km/h to the south

• 165 km/h to the north

• 310 km/h to the south

A glofer takes two putts to sink his ball in the hole once he is on the green. The first putt displaces the ball 6.00 m east, and the second putt displaces the ball 5.40 m south. What displacement would put the ball in the hole in one putt?

• 11.40 m southeast

• 8.07 m at 48.0° south of east

• 3.32 m at 42.0° south of east

• 8.07 m at 42.0° south of east

A girl riding a bicycle at 2.0 m/s throws a tennis ball horizontally forward at a speed of 1.0 m/s from a height of 1.5 m. At the same moment, a boy standing on the sidewalk drops a tennis ball straight down from a height of 1.5 m.

What's the initial speed of the girl's ball relative to the boy?

• 1.0 m/s

• 1.5 m/s

• 2.0 m/s

• 3.0 m/s

If the sign is 300 N, What is the tension for either wire?

• 96 N

• 150 N

• 196 N

• 233 N

Tags

NGSS.HS-PS2-1

Which of the following statements is ALWAYS true of an object in equilibrium?

• The object maintains its state of motion.

• The object is at rest.

• The object is not accelerating.

• The object's velocity is not changing.

• The sum of all forces acting on the object is 0.

Tags

NGSS.HS-PS2-2

How would you find the magnitude of a resultant vector that has an x component of 8 N and a y component of 6 N?

• Square Root of (8^2 + 6^2)

• Square Root of (8^2 - 6^2)

• Tan^-1 (8/6)

• Tan^-1 (6/8)

How would you find the direction of a vector that has an x component of 8 N and a y component of 6 N?

• Square Root of (8^2 + 6^2)

• Square Root of (8^2 - 6^2)

• Tan^-1 (8/6)

• Tan^-1 (6/8)

A runner races in the 100 meter dash.  It takes her 10 seconds to finish.  What is her average speed?

• 10 m/s
• 1000 m/s
• 100 seconds
• 10 seconds