Physics Q2 Summative Exam

If you were to stand next to a black hole with a mass equal to that of the sun, what do you think would happen to you?

• You will be pulled in and unable to escape.

• You will float away unaffected.

• You will experience a strong push away from it.

• You will feel a slight gravitational pull but remain safe.

When balancing a heavy object on one side, why might you extend your opposite leg outwards?

• to improve your posture.

• to increase your overall strength.

• to enhance your stability and balance.

• to reduce the load on your back.

What happens when a female gymnast moves from an extended position to a tucked position?

• Neither A nor B.

• Cannot be determined.

• She increases her rotational inertia.

• She decreases her rotational inertia.

Which of the forces pictured as acting upon the rod will produce a torque about an axis perpendicular to the plane of the diagram at the left end of the rod?

• F1

• F2

• Both A and B

• Neither

A uniform rod of mass 3 kg and length of 3.0 m is pivoted about an axis perpendicular to the rod and 1.0 m from its left end. Calculate the rotational inertia about this axis.

• 3.00 kg·m²

• 4.25 kg·m²

• 2.50 kg·m²

• 1.50 kg·m²

A 30-N force is exerted at the end of a lever arm that is 50-cm long. The force is applied at an angle of 90 degrees to the lever arm. What is the torque produced by the lever on the object? Show your solution.

• 1.5 N·m

• 15 N·m

• 30 N·m

• 60 N·m

When 100 J of work is done upon a flywheel, its angular speed increases from б0 rev/min to 180 rev/min. What is its moment of inertia?

• 0.204 kg/m³

• 0.63 kg/m³

• 0.024 kg/m³

• 0.404 kg/m³

The mass of Mars is approximately 6.4x10^23 kg and its radius is about 3389.5 km. Calculate the strength of the gravitational field on the surface of Mars. Show your solution.

• 3.71 N/kg

• 9.81 N/kg

• 1.62 N/kg

• 4.92 N/kg

A pendulum completes 15 swings in 30 s. What is the duration of one swing?

• 2 s

• 1.5 s

• -2.5 s

• 2.2 s

If an object submerged in a liquid displaces a volume of liquid equal to its weight and is then release, what will the object do?

• sink

• nothing happened

• goes up to the surface

• remain at its submerged position