A block and tackle system has 6 pulleys. If the efficiency of the machine is 60%, determine its mechanical advantages
A12.0
B10.0
C3.6
D1.8
View Explanation & Discuss
Question 42
waec2002
a load of mass120kg is raised vertically through a height of 2m in 30s by a machine whose efficiency is 100%. Calculate the power generated by the machine. [g = 10ms-2]
A60W
B80W
C100W
D120W
View Explanation & Discuss
Question 43
waec2002
Which of the following statements correctly defines quantitatively the work done by a force? the product of the force and the distance moved
Aparallel to the line of action of the force from a reference point
Bperpendicular to the line of action of the force from a reference point
Con a line through the reference point
Dby the object
View Explanation & Discuss
Question 44
waec2002
In the diagram above, AB represents a uniform rod of length 1.50m which is in equilibrium on a pivot at P, If AP = 40cm, calculate the mass of the rod. [g = 10ms-2]
A0.280kg
B0.400kg
C0.613kg
D0.800kg
View Explanation & Discuss
Question 45
waec2002
A spiral spring of natural length 30.0cm and force constant of 20Nm-1 is compressed to 20.0cm. Calculate the energy stored in the spring
A0.1J
B1.0J
C10.0J
D100.0J
View Explanation & Discuss
Question 46
waec2002
An object A is held in equilibrium as illustrated in the diagram above. Using the data on the diagram determine the magnitude, W of the weight of
A23N
B17N
C7N
D5N
View Explanation & Discuss
Question 47
waec2002
An object is acted upon by a system of parallel forces causing the object to be in static equilibrium. Which of the following statements is not correct?
AThe resultant of the parallel force is zero
Bthe algebraic sum of the moment of the forces is zero
Call the parallel forces must be equal in magnitude and in direction
Dthe sum of the forces in one direction must be equal to the sum of forces in the opposite direction
View Explanation & Discuss
Question 48
waec2002
An object is released from rest at a height of 25m. Calculate the time it takes to fall to the ground. [g = 10ms-2]
A25.00s
B10.00s
C2.50s
D2.24s
View Explanation & Discuss
Question 49
waec2002
A car takes off from rest and covers a distance of 80m on a straight road in 10s. Calculate the magnitude of its acceleration
A1.25ms-2
B1.60ms-2
C4.00ms-2
D8.00ms-2
View Explanation & Discuss
Question 50
waec2002
A man was moving round a circular path continuously for 4 minutes and covered the following distances in the times stated :
Distance (in metres) 200, 400, 600, 300
Time(in minutes) : 1, 2, 3, 4 respectively. Which of the following statements is correct about the motion of the man?
Athe man was moving without uniform velocity
Bthe speed was changing constantly
Cthe velocity was uniform
Dit was an instance of motion in which both speed and velocity are the same
View Explanation & Discuss
Question 51
waec2002
The magnitude of the force required to make an object of mass, m move with speed, v in a circular of radius r is given by the expression
A\(\frac{mr}{v}\)
B\(\frac{mr^2}{v}\)
C\(\frac{mv^2}{r}\)
D\(\frac{mv}{r^2}\)
View Explanation & Discuss
Question 52
waec2002
A boy travels 8 km eastward to a point B and then 6km northward to another point C. Determine the difference between the magnitude of displacement of the boy and distance travelled by him
A2.0km
B4.0km
C10.0km
D13.0km
View Explanation & Discuss
Question 53
waec2002
One common characteristics of solids, liquids and gasses is that?
Aall the three has fixed volume
Btheir molecule have the same size
Ctheir molecules are always in motion
Dall the three have the same inter molecular forces
View Explanation & Discuss
Question 54
waec2002
A solid weight 45N and 15N respectively in air and water. Determine the relative density of the solid
A0.33
B0.50
C1.50
D3.00
View Explanation & Discuss
Question 55
waec2002
A reservoir is filled with a liquid of density 2000kgm-3. Calculate the depth at which the pressure in the liquid will equal to 9100Nm-2 [g = 10ms-2]
A0.262m
B0.455m
C0.664m
D0.819m
View Explanation & Discuss
Question 56
waec2002
The force between the molecules of a liquid in contact with that of a solid is
Aadhesive
Bcohesive
Cmagnetic
Drepulsive
View Explanation & Discuss
Question 57
jamb2002
The colours seen on soap bubbles are due to
ADiffraction
BRefraction
CDispersion
DInterference
View Explanation & Discuss
Question 58
jamb2002
If the total force acting on a particle is zero, the linear momentum will
AIncrease
BDecrease
CBe Constant
DIncrease then decrease
View Explanation & Discuss
Question 59
jamb2002
A bead travelling on a straight line wire is brought to rest at 0.2 by friction. If the mass of the bead is 0.01kg and the coefficient of friction between the bead and the wire is 0.1, determine the work done by the friction
[g = 10ms\(^2\)]
A2 x 10\(^{-4}\)
B2 x 10\(^{-3}\)
C2 x 10\(^{-1}\)
D2 x 10\(^2\)
View Explanation & Discuss
Question 60
jamb2002
Which of the following statements is true of the properties of a moving coil galvanometer?
ATHe coil has a small area
BThere are strong hair springs to gives a large control panlel
CThere is a strong permanent magnet to give high magnetic flux
