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July 24, 2014

July 24, 2014

Posted by **lawrence** on Wednesday, October 12, 2011 at 11:51am.

(A) The passenger is in motion relative to the passer-by

(B) The passer-by is stationery relative to the passenger

(C) Both observers are in motion relative to each other

(D) The passer-by is in motion relative to the passenger

( 2.) Which of the following statements is not correct about reference frames?

(A) Laws of physics are invariant in inertial reference frames

(B) In non-inertial reference frames the motion of objects depend only on the interactions of constituent particles among themselves

(C) Any reference frame moving at constant velocity with respect to an inerial refernce frame is also inertial

(D) If the coordinate axes of a reference frame attached to an object remain fixed in space then the object is at rest

( 3.) What are the dimensions of power (time rate of change of expending energy)

ML/T^2

ML^2/T^3

ML^2/T^2

M^2L^2/T^3

( 4.) Express the speed of a car traveling at 80km/hr in mm/s

2.22x10^4

2.22x10^3

22.2x10^4

2.22x10^5

( 5.) Two forces act on a point object as follows: 100N at 170derees and 100N at 50degrees. Find their resultant force

110N at 50degrees

110N at100degrees

100N at 110degrees

100N at 50degrees

( 6.) Given three vectors a = -i-4j+2k, b = 3i+2j-2k, c = 2i-3j+k, calculate a.(bxc)

-6

6

9

-9

( 7.) The resultant of vectors A and B has a magnitude of 20 units. A has a magnitude of 8 units, and the angle between A and B is 40degrees. Calculate the magnitude of B

12.6

16.2

14.8

18.4

( 8.) A man leaves the garrage in his house and drives to a neighbouring town which is twenty kilometres away from his house on sight-seeing. He returnes home to his garrage two hours after. What is his average velocity from home in Km/h?

10

0

20

40

( 9.) A monkey in a perch 20m high in a tree drops a coconut above the head of a zoo keeper as he runs with a speed 1.5m/s benaeth the tree. How far behind him in metres does the coconut hit the ground?

2.25

3.06

2.02

3.03

( 10.) A monkey in a perch 20m high in a tree drops a coconut above the head of a zoo keeper as he runs with a speed 1.5m/s benaeth the tree actually intending to hit the toes of the zoo keeper, how early in seconds should the coconut be dropped by the monkey to achieve his aim?

1.50

2.04

1.35

3.02

( 11.) Which of the follwing statements is correcct?

An object can have a constant velocity even though its speed is changing

An object can have a constant speed even though its velocty is changing

An object can have zero acceleration and eventually reverses its direction

An object can have constant velocity even though its acceleration is not zero

( 12.) A boat propelled so as to travel with a speed of 0.50m/s in still water, moves directly (in a straight line) across a river that is 60m wide. The river flows with a speed of 0.30m/s. How long in seconds does it take the boat to cross the river?

120

36

200

150

( 13.) A boy intends to move an m kg - crate across the floor by applying a constant force P newtons on it.The coeficient of friction between the floor and the crate is µ. Which of these is the best option for his task?

Pull the crate with P applied horizontally

Push the crate with P inclined at an angle above the horizontal

Pull the crate with P inclined at an angle above the horizontal

Pull the crate with P inclined an angle below the horizontal

( 14.) A 50kg boy suspends himself from a point on a rope tied horizontally between two vertical poles. The two segments of the rope are then inclined at angles 30 degrees and 60 degrees respectively to the horizontal.The tensions in the segments of the rope in newtons are

25.0 and 43.3

50.0 and 25.0

100.0 and 43.5

100.0 and 25.0

( 15.) Which of the following physical concepts best explains why passengers in fast moving cars should always fasten their seat-belts?

moment

terminal velocity

inertia

centripetal force

( 16.) Which of the following does not contribute to the determination of stability of on an object?

unstable equilibrium

stable equilibrium

neutral equilibrium

central equilibrium

( 17.) A rope suspended from a ceiling supports an object of weight W at its opposite end. Another rope tied to the first at the middle is pulled horizontally with a force of 30N. The junction P of the ropes is in equilibrium. Calculate the weight W and the tension T in the upper part of the first rope

27.2N and 39.2N

40.5N and 62.5N

30.4N and 53.7N

16.6N and 27.3N

( 18.) A 150-kg ladder leans against a smooth wall, making an angle of 30 degrees with the floor. The centre of gravity of the ladder is one-third the way up from the bottom. How large a horizontal force must the floor provide if the ladder is not to slip?

28.7N

54.3N

37.6N

63.4N

( 19.) A body hangs from a spring balance supported from the roof of an elavator. If the elavator has an upward acceleration of 3m/s2 and the balance reads 50N, what is the true weight of the body?

50.0N

28.3N

38.3N

39.8N

- physics -
**temidayo**, Thursday, April 26, 2012 at 4:47am1a,2b,3a,4c,5c,6d,7b,8a,9b,10c,11a,12b,13a,14a,15b,16a,17c,18a,19b,20c......please i need the correction.

- physics -
**Anonymous**, Wednesday, January 16, 2013 at 9:32amBoth observers are in motion relative to each other

- physics -
**Anonymous**, Wednesday, January 16, 2013 at 9:44am1. Both observers are in motion relative to each other

2.In non-inertial reference frames the motion of objects depend only on the interactions of constituent particles among themselves

3. ML/T^2

4.2.22x10^4

5.110N at100degrees

- electrical engineering -
**Daramola**, Thursday, January 17, 2013 at 11:36am3c, 5c

- physics -
**g.t**, Wednesday, May 29, 2013 at 8:35am1-5(cabac)

6-10(dbabb)

11-15(aacab)

16-20(daacc

- physics -
**Okon Emmanuel eno**, Monday, October 7, 2013 at 6:15am1 the passenger is in motion relative to the passer by 2 the passer by is stationary relative to the passenger 3 Both observers are in motion relative to each other 4 the passer by is in motion relative to the passenger

- physics -
**Anonymous**, Sunday, March 23, 2014 at 1:33pm1.a man leaves the garrage in his house and drives to a neighbouring town which is twenty kilometres away from his house on sight seeing. He returns home to his garrage two hours after. What ir his average velocity from home in km/h?a.10 b.0 c.20 d.40

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