Science 9 Fourth Quarter Examination

A car moves with uniform acceleration along a straight road. Which of the following statements is true?

• The velocity of the car remains constant

• The acceleration of the car changes with time

• The car covers equal distances in equal intervals of time

• The velocity of the car increases uniformly with time

A ball is thrown horizontally from the top of a tower. Which of the following statements is true?

• The horizontal velocity remains constant

• The vertical velocity remains constant

• Both horizontal and vertical components of velocity increase

• The acceleration is zero in both directions

A body is dropped from a height. If air resistance is negligible, what happens to its speed as it falls?

• Increases linearly with time

• Remains constant

• Decreases linearly with time

• Becomes zero at maximum height

Which of the following remains constant during the free fall of an object?

• Velocity

• Acceleration

• Potential energy

• Kinetic energy

A projectile reaches its maximum height in 2 seconds. What is its initial vertical velocity component? (Take g=10 m/s²)

• 5 m/s

• 10 m/s

• 20 m/s

• 40 m/s

Which of the following conditions must be met for work to be done on an object?

• A force must be applied

• The object must move in the direction of the applied force

• The object must remain at rest

• Both a and b

Work is said to be negative when:

• The force is applied in the direction of displacement

• The displacement is in the opposite direction of the force

• No force is applied

• The force and displacement are perpendicular

What is the SI unit of work?

• Watt

• Joule

• Newton

• Pascal

A man carries a heavy box and walks on a horizontal road. What is the work done by him on the box?

• Positive work

• Zero work

• Negative work

• Cannot be determined

If a force of 10 N moves an object 5 m in the direction of the force, the work done is:

• 2 J

• 15 J

• 50 J

• 500 J