IB-A1 to A.3 review

A car has an initial speed of 16 m s. It decelerates at 4.0 m s until it stops. What is the distance travelled by the car?

• 4 m

• 16 m

• 32 m

• 64 m

A block of mass 2.0 kg accelerates from a speed of 15 m s to a speed of 20 m s 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. What is the work done by the force?

• 50 J

• 40 J

• 32 J

• 20 J

A person stands in an elevator (lift). The total mass of the person and the elevator is 800 kg. The elevator accelerates upward at 2.0 m s. What is the tension in the cable?

• 1.6 kN

• 6.4 kN

• 8.0 kN

• 9.6 kN

A bird of weight W sits on a thin rope at its midpoint. The rope is almost horizontal and has negligible mass. The tension in the rope is

• less than W/2

• equal to W/2

• between W/2 and W

• greater than W

Planets X and Y orbit the same star. The average distance between planet X and the star is √5 times greater than the average distance between planet Y and the star. What is the orbital period of planet Y?

• √5

• 3√5

• 2√5

• √(5^3)

A block of mass 2.0 kg accelerates from a speed of 15 m s to a speed of 20 m s 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. What is the work done by the force?

• 50 J

• 40 J

• 32 J

• 20 J

A toy balloon floats at the end of a string. A wind blows horizontally to the right. The balloon is in translational equilibrium. What is the free-body diagram of the forces acting on the balloon?

A body of height 40 cm and uniform cross-sectional area floats in water. 10 cm of the height of the body remains above the water line. The density of water is ρ. What is the density of the body?

• ρ/4

• ρ/3

• 2ρ/3

• 3ρ/4