PHYSICS 120

profilerdmut
phyhomework.docx

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)

1.

2.

3.

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

1.

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