Test SL 2025

A block of mass 2.0 kg accelerates from a speed of 15 m s⁻¹ to a speed of 20 m s⁻¹ without changing its direction. What impulse acts on the block?

• 2.5 N s

• 5.0 N s

• 10 N s

• 17.5 N s

A net force of 8.0 N accelerates a 4.0 kg body from rest to a speed of 5.0 m s⁻¹. What is the work done by the force?

• 50 J

• 40 J

• 32 J

• 20 J

When a horizontal spring is extended by a distance x, the force acting on the spring is F. The extension of the spring is directly proportional to the force. What is the energy stored in the spring?

• F/2x

• Fx

• Fx/2

An object of mass 6.0 kg is accelerated horizontally from rest in 4.0 s to reach a speed of 10 m/s. What is the average power delivered to the object?

• 7.5 W

• 15 W

• 75 W

• 150 W

An object is launched upwards at an initial velocity +u at an angle of θ to the horizontal. Air resistance is negligible. At a later time the object has a vertical displacement of zero. What are the horizontal component of the velocity and the vertical component of the velocity at this later time?

• Horizontal component: u cos θ, Vertical component: u sin θ

• Horizontal component: u cos θ, Vertical component: –u sin θ

• Horizontal component: u sin θ, Vertical component: u cos θ

• Horizontal component: u sin θ, Vertical component: –u cos θ

What is the final velocity of the object?

• 0 m/s

• 5 m/s

• 10 m/s

• 20 m/s

An object of mass m is accelerated from rest by a constant resultant force F. The final velocity of the object is v. What energy is transferred to the object during the acceleration?

The resistive force F that acts on an object moving through a fluid at speed v is given by F = kv where k is a constant. What is the unit of k?

• (θ₂ − θ₁)

• (θ₂ − θ₁) + 273

• (θ₂ − θ₁) − 273

• 273 − (θ₂ − θ₁)

A car accelerates uniformly. The car passes point X at time t₁ with velocity v₁ and point Y at time t₂ with velocity v₂. The distance XY is s. The following expressions are proposed for the magnitude of its acceleration a: I. a = 2s / (t₂ − t₁)² II. a = (v₂² − v₁²) / 2s III. a = (v₂ − v₁) / (t₂ − t₁) Which is correct?

• A. I and II only

• B. I and III only

• C. II and III only

• D. I, II and III