# What is the magnitude of A.B?   e.g. the magnitude of the dot product of A and B

phy 120

a vector is given as A = 3x^ + 4y^ and a second is given by F = -7x^ =3y^

what is the magnitude of A + F

 2.56 5.74 11 8.06

A ball is shot at 40 m/s at an angle of 55o above horizontal.  what is the component of the velocity along the vertical axis?

 22.9 m/s 32.7 m/s 57.1 m/s 12.6 m/s

A vector is given by b = 14 x^ – 20y^, What is the angle with respect to the +x^ axis?

 55o 45.5o 44.4o 15.4o

A vector is given by A = 4x^ + 2y^ and vector B = 5x^ + 2y^

What is the magnitude of A.B?   e.g. the magnitude of the dot product of A and B

note you will need the magnitude of each vector and the angle between them

 24 86

1. A vector has a magnitude of 30 and it points at 25o to the negative side of the positive y axis.  Assume a standard orthogonal coordinate system where pos y is up and pos x is to the right.

what are the components?  (x,y)

 (-12.6, -27.2) (-12.6, 27.2) (27.2,-12.6) (-27.2, -12.6)

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4. A box is moving at 6 m/s, it accelerates at 1.4 m/s2 and reaches a final velocity of 24 m/s.  how much time did this take?

 0.4 s -4.2 s 6 s 12.8 s

1. i walked for 2 km at a constant speed of 3 m/s then turned right and walked 6 km at 2 m/s.

What was my average velocity?

 1.96 m/s 1.6 km/hr 4.6 m/s 12.8 km/s

1. i was moving at 8 m/s initially, i then slowed to 2 m/s in a minute. how far did i travel?

 220 m 660 m 300 m 1024 m

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2. i throw ball  up at 4 m/s, how high does the ball reach?

 1.6 m 24 cm 2.4 m 82 cm

1. A book falls, from rest, off a 3 m shelf hits the ground at 7.67 m/s   How much time was the book in the air?

 1.56 s 0.78 s 0.39 s 1 s