CSS - PMS - CCE - PCS - General Science
Mechanics - Power
What is power in mechanics?
A. Force multiplied by time only
B. Momentum per unit time only
C. Rate of doing work or transferring energy
D. Mass per unit volume
Correct Answer: C
Power measures how quickly work is done.
CSS - PMS - CCE - PCS - General Science
Mechanics - Motion
Which graph's slope gives velocity?
A. Temperature-time graph only
B. Mass-time graph
C. Position-time graph
D. Force-area graph
Correct Answer: C
The derivative or slope of position versus time is velocity.
CSS - PMS - CCE - PCS - General Science
Mechanics - Motion
What is uniform motion?
A. Motion at constant velocity
B. Motion with zero time
C. Motion with changing mass only
D. Motion with changing velocity always
Correct Answer: A
Uniform motion means equal displacements in equal time intervals in a constant direction.
CSS - PMS - CCE - PCS - General Science
Mechanics - Motion
Can distance be nonzero while displacement is zero?
A. Only in free fall
B. No, never
C. Yes, after returning to the starting point
D. Only in space
Correct Answer: C
A round trip can have positive path length but zero net displacement.
CSS - PMS - CCE - PCS - General Science
Mechanics - Motion
What is displacement?
A. Total path length only
B. Mass change
C. Time interval only
D. Change in position from initial to final point with direction
Correct Answer: D
Displacement is a vector from starting position to ending position.
CSS - PMS - CCE - PCS - General Science
Mechanics - Motion
What is distance?
A. Straight-line displacement only
B. Speed multiplied by mass
C. Force per unit time
D. Total path length traveled
Correct Answer: D
Distance is a scalar path-length quantity.
CSS - PMS - CCE - PCS - General Science
Mechanics - Motion
What is motion?
A. Change in position of an object with time relative to a reference frame
B. Change in temperature only
C. Absence of position
D. Change in mass only
Correct Answer: A
Motion is defined relative to a chosen reference frame.
CSS - PMS - CCE - PCS - General Science
Mechanics - Momentum
Why do airbags reduce injury risk in a collision?
A. They increase stopping time, reducing average force for a given momentum change
B. They increase acceleration sharply
C. They increase momentum
D. They eliminate mass
Correct Answer: A
Spreading the same momentum change over more time lowers average force.
CSS - PMS - CCE - PCS - General Science
Mechanics - Momentum
What is impulse equal to?
A. Velocity only
B. Mass only
C. Change in momentum
D. Power
Correct Answer: C
Impulse J = FΔt equals Δp.
CSS - PMS - CCE - PCS - General Science
Mechanics - Momentum
What principle applies to total momentum in an isolated system?
A. It always increases
B. It equals temperature
C. It is conserved
D. It always becomes zero
Correct Answer: C
With no net external impulse, total momentum remains constant.
CSS - PMS - CCE - PCS - General Science
Mechanics - Momentum
Which equation defines momentum?
A. p = F/A
B. p = V/I
C. p = m/v
D. p = mv
Correct Answer: D
Linear momentum is mass times velocity.
CSS - PMS - CCE - PCS - General Science
Mechanics - Momentum
What is the SI unit of momentum?
A. kg·m/s
B. kg/m³
C. N/m²
D. J/s
Correct Answer: A
Momentum combines mass in kilograms and velocity in meters per second.
CSS - PMS - CCE - PCS - General Science
Mechanics - Momentum
What is linear momentum?
A. Mass divided by velocity
B. Product of mass and velocity
C. Energy per unit time
D. Force divided by area
Correct Answer: B
Momentum p = mv.
CSS - PMS - CCE - PCS - General Science
Mechanics - Mass & Weight
Would a person's mass change on the Moon?
A. Yes, it becomes zero
B. Only if wearing a suit
C. Yes, it doubles
D. No
Correct Answer: D
Mass remains essentially the same, while weight decreases because lunar gravity is weaker.
CSS - PMS - CCE - PCS - General Science
Mechanics - Mass & Weight
Which formula relates weight W, mass m and gravitational acceleration g?
A. W = m/g
B. W = mg
C. W = mv
D. W = ma²
Correct Answer: B
Weight equals mass times gravitational field acceleration.
CSS - PMS - CCE - PCS - General Science
Mechanics - Mass & Weight
What is the SI unit of weight?
A. Kilogram
B. Second
C. Meter
D. Newton
Correct Answer: D
Weight is a force, so it is measured in newtons.
CSS - PMS - CCE - PCS - General Science
Mechanics - Mass & Weight
What is the SI unit of mass?
A. Kilogram
B. Watt
C. Joule
D. Newton
Correct Answer: A
Mass is measured in kilograms.
CSS - PMS - CCE - PCS - General Science
Mechanics - Mass & Weight
What is weight?
A. Gravitational force acting on an object
B. Density
C. Amount of matter
D. Momentum
Correct Answer: A
Weight depends on local gravitational field strength.
CSS - PMS - CCE - PCS - General Science
Mechanics - Mass & Weight
What is mass?
A. Gravitational force on an object
B. Measure of the amount of matter and inertia of an object
C. Speed of an object
D. Volume only
Correct Answer: B
Mass is intrinsic and is measured in kilograms.
CSS - PMS - CCE - PCS - General Science
Mechanics - Friction
What factor often increases dry friction between two surfaces?
A. Removing contact
B. Greater normal force
C. Lower contact force only
D. Perfect vacuum alone
Correct Answer: B
In simple models, friction is approximately proportional to normal force.