Physics Study Notes Overview

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What is the acceleration of both the feather and the lead ball when dropped in a vacuum?

1.6 m/s²
They are equal (correct)
0 m/s²
9.8 m/s²

What primarily affects the falling speed of the feather compared to the lead ball on Earth?

Shape of the objects
Air resistance (correct)
Material of the objects
Weight of the objects

On the Moon, what would the acceleration due to gravity be for both the feather and the lead ball?

20 m/s²
1.6 m/s² (correct)
0 m/s²
9.8 m/s²

Which formula represents the force that tends to pull the block down the inclined plane?

F = (200)(sin 20°) (C) Signup and view all the answers

Which principle allows the feather and the lead ball to experience the same acceleration in a vacuum?

Galileo's Law of Falling Bodies (D) Signup and view all the answers

What is the role of air resistance when a feather and lead ball are dropped together on Earth?

It slows the feather down significantly. (D) Signup and view all the answers

When analyzing an inclined plane, what component of weight acts down the plane?

Parallel component (B) Signup and view all the answers

How does the mass of an object influence its acceleration in free fall in a vacuum?

It has no effect on acceleration. (A) Signup and view all the answers

Which group of quantities comprises entirely vector quantities?

displacement, acceleration, force (A) Signup and view all the answers

What is the kinetic energy of an object if no external work has been done on it?

It equals the work done to stop it. (B) Signup and view all the answers

Which of the following is NOT an acceptable unit of potential energy?

gram·cm/s² (B) Signup and view all the answers

At what angle should the roadway be banked to negotiate a curve at 12 m/s without friction?

16° (C) Signup and view all the answers

Which of the following describes a scalar quantity?

Power (D) Signup and view all the answers

How is the work done on an object related to its kinetic energy?

Work done is equal to the change in kinetic energy. (D) Signup and view all the answers

Which option contains a mixture of scalar and vector quantities?

acceleration, speed, work (A) Signup and view all the answers

What is the relationship between work and energy?

Work is the transfer or transformation of energy. (A) Signup and view all the answers

Which of the following statements about the joule is correct?

It is a unit of energy in the SI system. (B) Signup and view all the answers

Which of the following units cannot be used to express potential energy?

Gram·cm/s² (B) Signup and view all the answers

In an elevator rising at a constant speed, which of the following is inaccurate?

Gravitational potential energy remains constant. (B) Signup and view all the answers

A pendulum at the bottom of its swing has which of the following characteristics?

It has no kinetic energy. (D) Signup and view all the answers

What can be inferred about the mechanical energy of an elevator rising at constant speed?

It remains constant since kinetic and potential energy are conserved. (A) Signup and view all the answers

In which scenario would the elevator's gravitational potential energy remain constant?

When the elevator is stationary on the fifth floor. (D) Signup and view all the answers

If an elevator’s speed doubles while rising, how does its kinetic energy change?

It quadruples. (C) Signup and view all the answers

How is energy expressed when using the unit foot-pound?

It refers to work done over a distance in the Imperial system. (C) Signup and view all the answers

What is the acceleration of the elevator when it is moving at a constant speed?

Zero acceleration (A) Signup and view all the answers

If a woman lifts a barbell the same distance but takes twice as long, how does the work done change?

It remains the same (C) Signup and view all the answers

How is the mechanical energy of the Earth-elevator system affected if no non-conservative forces are at work?

It remains constant (A) Signup and view all the answers

What height must a 2-kg block be lifted to increase its gravitational potential energy by 500 J starting from 20 m above Earth's surface?

46 m (C) Signup and view all the answers

What force must be overcome when pulling a crate up a frictionless slope at constant speed?

Gravity (B) Signup and view all the answers

In the scenario where the mechanical energy is constant, how does the increase in gravitational potential energy relate to other forms of energy?

It is balanced by the work done by a cable (C) Signup and view all the answers

What is the formula to calculate the work done based on gravitational potential energy change?

Work = mg(hf – hi) (C) Signup and view all the answers

When a load is lifted at constant speed, which of the following is true about the forces acting on the load?

The net force is zero (B) Signup and view all the answers

What is the total mass of the 20 people being moved by the escalator?

1200 kg (B) Signup and view all the answers

How much total work is done in moving the 20 people up 5 m?

58800 J (B) Signup and view all the answers

What is the time period used for calculating power in this scenario?

1 minute (C) Signup and view all the answers

What is the approximate power required to lift the 20 people using the escalator?

1000 W (A) Signup and view all the answers

What does the formula for work done in this scenario primarily depend on?

The height difference and the number of people (D) Signup and view all the answers

Which equation is primarily used to calculate the power in this context?

Power = Work / Time (B) Signup and view all the answers

What is the gravitational potential energy change when lifting one person 5 m?

3000 J (C), 3000 J (D) Signup and view all the answers

How is the angle Θ related to the calculations of work done in the context provided?

It has no relevance. (C) Signup and view all the answers

What is the relationship between tension, gravitational force, and centripetal force in the context of a swinging ball on a string?

Tension is equal to the gravitational force plus the centripetal force. (A) Signup and view all the answers

At the lowest point of the swing, if the radius of the circular path is 0.5 m, what is the potential energy converted to kinetic energy as the ball descends?

It entirely converts to kinetic energy if released from the top. (A) Signup and view all the answers

Which block requires the greatest initial speed to cover the same distance before coming to rest, considering all forces acting against it?

Block moving up the incline. (D) Signup and view all the answers

When ranking the initial speeds of the three blocks, which is the order from least to greatest based on the energy mechanics involved?

3, 1, 2 (B) Signup and view all the answers

Why does Block 3 (moving down the incline) need less initial speed compared to Block 1 (horizontal surface)?

Gravity assists Block 3 in its motion. (C) Signup and view all the answers

In the energy transfer from potential to kinetic energy, what factors could impact the speed of a block on a frictionless track?

All of the above. (D) Signup and view all the answers

If a block is sliding down a frictionless incline, into what form of energy is its gravitational potential energy primarily converted?

Kinetic energy. (A) Signup and view all the answers

What is the total mechanical energy of a system involving the swinging ball and gravitational force?

It remains constant throughout the swing. (A) Signup and view all the answers

Feather and lead ball acceleration in a vacuum

In a vacuum, both a feather and a lead ball fall with the same acceleration due to gravity, regardless of their mass.

Acceleration due to gravity on the Moon

The acceleration due to gravity on the Moon is approximately 1.6 m/s².

Force pulling a block down an incline

The force pulling a block down an inclined plane is equal to the weight of the block multiplied by the sine of the incline angle.

Force components on an incline

The weight of an object on an incline is broken down into components, one parallel to the incline (driving force) and one perpendicular (normal force).