i need answers! i'll PICK THE BEST ANSWERS!
thank you
1)A student pulls a box across a horizontal floor at a constant speed of 4.0 meters per second by exerting a constant horizontal force of 45 newtons. Approximately how much work does the student do against friction in moving the box 5.5 meters across the floor?
A. 45 J
B. 180 J
C. 250 J
D. 740 J
2)A force of 5.0 newtons moves a 2.0-kilogram object a distance of 3.0 meters in 3.0 seconds. How much work is done on the object?
a. 1.0 J
b. 10. J
c. 15 J
d. 30. J
3) The area affected by a magnet is called a magnetic
a. field
b. node
c. pole
d. storm
4)Which element is not magnetic?
a. Fe
b. Co
c. Al
d. Ni
5) Which is magnetic?
Fe
Cu
Hg
Br
2007-03-23 13:19:27 · 4 answers · asked by couturevogue 3 in Science & Mathematics ➔ Physics
Hi. 3, 4, and 5 deal with magnetism. The AREA of a magnetic influence is a field (think of an open field). Aluminum is not magnetic but iron (ferrous metal) is magnetic.
2007-03-23 13:29:31 · answer #1 · answered by Cirric 7 · 1⤊ 0⤋
1) W = F*d
W = 45N * 5.5m = 245.5 N*m = 250 J
2) W = F*d
W = 5.0N * 3.0m = 15 N*m = 15 J
3) The area affected by a magnet is called a magnetic field.
4) Aluminum (Al) is not magnetic.
5) Iron (Fe) is magnetic.
2007-03-23 20:44:19 · answer #2 · answered by JaniesTiredShoes 3 · 0⤊ 0⤋
1. W = Fd
W = (5.5m)(45N)
W = 247.5 N or with 2 sig figs, 250 J (C)
2. W = Fd
W = (5.0N) (3.0m)
W = 15 J (C)
3. A. Field
4. C. Al
5. A. Fe
Hope these help.
2007-03-23 20:41:03 · answer #3 · answered by Anonymous · 1⤊ 0⤋
work = force * distance
1) work = 45N * 5.5m
work = 245.5J
2) work = 5N * 3m
work = 15J
2007-03-23 20:31:44 · answer #4 · answered by 7 · 1⤊ 0⤋