2019 - JAMB Physics Past Questions and Answers - page 10
The volume of a stone having an irregular shape can be determined using?
meter rule
measuring cylinder
vernier calliper
micrometer screw gauge
The volume of object is equal to the volume of liquid it will displace in a container, such as measuring cylinder.
In Sunlight, a blue flower looks blue because we see the flower by the light it
receives from our eyes
disperses
absorbed
reflect
A body moves in SHM between two point 20m on the straight line Joining the points. If the angular speed of the body is 5 rad/s. Calculate its speed when it is 6m from the center of the motion.
20 m/s
30 m/s
40 m/s
50 m/s
At 20m apart,
a = 10m, x = 6m, A = 5
v = ω\(\sqrt{A^2 - X^2}\) = 5\(\sqrt{10^2 - 6^2}\) = 40m/s
v = 40m/s
The diagram shows a uniform meter rule AB which balances horizontally at the 90cm mark when a mass of 0.2kg is suspended from B. Calculate the mass of the meter rule.
0.05kg
0.20kg
0.80kg
1.00kg
M\(_r\)(90 - 50) = 0.2(100 - 90)
40M\(_r\) = 0.2 × 10
| M\(_r\) | = | 2
40 |
= | 0.05kg |
The equilibrium position of objects in any field corresponds to situation of
equipotential energy
maximum potential energy
minimum potential energy
maximum kinetic energy
Potential energy (PE) = mgh = mgh = force × distance
Hence, 0 × d = 0
The height at which the atmosphere cases to exist is about 80km. If the atmospheric pressure on the ground level is 760mmHg, the pressure at a height of 20km above the ground level is
(ρm = 13.6g/cm\(^3\) ρ = 0.00013g/cm\(^3\) )
380mmHg
570mmHg
190mmHg
480mmHg
ρ\(_m\)h\(_m\) = ρ\(_a\)h\(_a\)
13.68(760 - p) × 10\(^{-3}\) = 13 × 10\(^{-5}\)(20 × 10\(^3\))
| 760 | - | p | = | 13 × 10\(^{-5}\) × 20 × 10\(^{3}\)
13.68 × 10\(^{-3}\) |
= | 19.00 | × | 10\(^{1}\) |
760 - p = 190
p = 760 - 190
p = 570mmHg
A cone is in unstable equilibrium has its potential energy
decreased
increased
unchanged
oscillating
Unstable equilibrium is a state of equilibrium in which a small disturbance will produce a large change. Potential energy decreases as the height decreases.
A mass of 0.5kg is whirled in a vertical circle of radius 2m at a steady rate of 2 rev/s. Calculate the centripetal force
164N
160N
158N
172N
ω = 2πF = 2π × 2 = 4πrad\(^{-1}\)
Centripetal force, Fc = mrω\(^2\)
Fc = 0.5 × 2 × (4π)\(^2\)
Fc = 160N
A body was slightly displaced from its equilibrium position. Which one of the following is a condition for its stable equilibrium
an increase in the kinetic energy of the body
an increase in the potential energy of the body
an increase in the potential energy of the body
an increase in the height of the body
A stable equilibrium is a state in which a body tends to return to its original position after being disturbed.
Which of the following readings cannot be determined with a meter rule?
2.56cm
2.25cm
2.50cm
2.05cm
For a meter rule with reading accuracy of 0.5mm or 0.05cm, measurement is M ± 0.05cm i.e 2.00, 2.05, 2.50, 2.55, etc.
Hence, it cannot read 2.56cm.