Exam 3: Vectors and Two-Dimensional Motion

A car is initially moving at 20 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?

Plane A is flying at 400 mph in the northeast direction relative to the earth.Plane B is flying at 500 mph in the north direction relative to the earth.What is the speed of Plane B as observed from Plane A?

Jack pulls a sled across a level field by exerting a force of 110 N at an angle of 30 $\degree$ with the ground.What are the parallel and perpendicular components, respectively, of this force with respect to the ground?

A particle moves east at constant velocity for a time interval DT.It then moves north at a constant velocity, with the same speed as before, for another time interval DT.Finally it moves east again with the original velocity.At the instant an additional time interval DT has elapsed, which of the following are true about the average velocity and the average acceleration for the motion described?

Superguy is flying at treetop level near Paris when he sees the Eiffel Tower elevator start to fall (the cable snapped).His x-ray vision tells him Lois LaTour is inside.If Superguy is 1.00 km away from the tower, and the elevator falls from a height of 240 m, how long does Superguy have to save Lois, and what must be his average speed?

Arvin the Ant is on a picnic table.He travels 30 cm eastward, then 25 cm northward, and finally 15 cm westward.What is the magnitude of Arvin's net displacement?

A river flows due east at 3.0 m/s.A boat crosses the 300-m-wide river by maintaining a constant velocity of 10 m/s due north relative to the water.If no correction is made for the current, how far downstream does the boat move by the time it reaches the far shore?

Four vectors all have the same magnitude.Vector 1 is at 30 $\degree$ , Vector 2 is at 135 $\degree$ , vector 3 is at 240 $\degree$ , and Vector 4 is at 315 $\degree$ .Which vector has the greatest magnitude x-component and which vector has the greatest magnitude y-component?

A ball is launched from ground level at 30 m/s at an angle of 35 $\degree$ above the horizontal.How far does it go before it is at ground level again?

Vector 1 is 7 units long and is at 70 $\degree$ Vector 2 is 5 units long and is at 225 $\degree$ .Vector 3 is 3 units long and is at 150 $\degree$ .Which vector has equal magnitude components?

Vectors , , and have magnitudes 6, 11, and 20.When these vectors are added, what is the least possible magnitude of their resultant?