Alex Gruest, Diego Gomez, Juan Muñoz - Gravitational Motion, Rotational Motion, Work, Energy

Question 1

What is work? - Remember

Answer 1

Work is equal to the product of the magnitude of the force and magnitude of displacement times the cosine of the angle between them.

Question 2

What is the definition of energy? - Remember

Answer 2

It´s the capacity for doing work.

Question 3

Can energy be lost? - Remember

Answer 3

No energy can’t be lost, according to the law of conservation of energy “energy states that energy can neither be created nor destroyed”. The energy just becomes less useful

Question 4

What is motion? - Remember

Answer 4

Motion is the change with time of the position or orientation of a body.

Question 5

What is gravitational motion - Remember

Answer 5

The natural phenomenon of attraction between physical objects with mass or energy.

Question 6

What is the equation of work? - Identify

Answer 6

W = fd , FORCE * DISTANCE

Question 7

What equation is used in order to find the Average Angular Velocity of an object? - identify

Answer 7

The angular velocity equals the angular displacement divided by the time required to make the rotation.

Question 8

What is power? - Identify

Answer 8

Power is the amount of energy transferred or converted per unit of time.

Question 9

What is the equation for Power? - Identify

Answer 9

P = E/t: This formula is also called the mechanical power equation. Here E stands for energy in joule and t stands for time in seconds.

Question 10

What is the unit of torque? - Identify

Answer 10

Nm, which is Newton Meters

Question 11

A sailor pulls a boat a distance of 30.0 m along a dock using a rope that makes a 25.0° angle with the horizontal. How much work does the rope do on the boat if its tension is 255 N? - Calculate

Answer 11

W = 6.93 * 10 (to the power of 3) J

Question 12

The rotational velocity of a merry-go-round is increased at a constant rate from 1.5 rad/s to 3.5 rad/s in a time of 9.5 s. What is the rotational acceleration of the merry-go-round? - Calculate

Answer 12

The rotational acceleration is 0.21 rad/s^2

Question 13

A meter stick is balanced at the 50.0 cm mark. You tie a 10.0 N weight at the 15.0 cm mark. Where should a 30.0 N weight be placed so the meter stick will again be balanced? - Calculate

Answer 13

It should be placed at 61.7 m.

Question 14

If a bowling ball weighing 5 kg is dropped from a 30-meter tall building, how much work is being done if the acceleration due to gravity is 9.8 m/s^2 (Hint: F = m*a) - Calculate

Answer 14

The work done is 1,470 J.

Question 15

How much gravitational potential energy does a 75 kg diver have stepping off the edge of a 5 m platform? - Calculate

Answer 15

The diver is making 3,675 J.

Question 16

A hockey player uses a stick to apply a constant 4.50-N force forward to a 105-g puck sliding on ice over a displacement of 0.150 m forward. How much work does the stick do on the puck? - Understand

Answer 16

W = Fd cos o
= (4.50 N) (0.150 M) (cos 0 )
= 0.675 J

Question 17

A 22.0-kg tree limb is 13.3 m above the ground. During a tropical storm, it falls on a roof that is 6.0 m above the ground.

a. Find the kinetic energy of the limb when it reaches the roof. Assume that the air does no work on the tree limb. - Understand

Answer 17

= 0.0 J * 1.6*10(power 3) J - 0.0 J

= 1.6 * 10(power 3) J

Question 18

b. What is the limb’s speed when it reaches the roof? (Use info of past flashcard) - Understand

Answer 18

= 12 m/s

Question 19

An electric motor lifts an elevator 9.00 m in 15.0 s by exerting an upward force of 1.20×104 N. What power does the motor produce in kW? - Understand

Answer 19

P = w/t
= Fd/t
= (1.20 * 10(power 4) N)(9.00 M) / (15.0 s)
= 7.20 kW

Question 20

A sailor pulls a boat a distance of 30.0 m along a dock using a rope that makes a 25.0° angle with the horizontal. How much work does the rope do on the boat if its tension is 255 N? - Understand

Answer 20

W = Fd cos 0
= (255 N)(30.0 M)(cos 25.0)
= 6.93 * 10 (to the power of 3) J

Question 21

You are jumping on a trampoline. When you are at highest point in the air, what kind of energy is that? - Random

Answer 21

Is Potential Energy.

Question 22

Work is a measurement of how much force is applied over a certain … ? - Random

Answer 22

… Distance

Question 23

Both work and energy are measured in … ? - Random

Answer 23

Joules, both are measured in Joules.

Question 24

As an object’s mass increases, its gravitational pull will … ? - Random

Answer 24

Increase, the gravitational pull increases

Question 25

What is gravitational rotation? - Remember

Answer 25

Rotational gravity, is thus the appearance of a centrifugal force in a rotating frame of reference

Question 26

What is gravitational motion? - Remember

Answer 26

It´s the force of attraction that bodies exert on one another as a result of their mass.

Question 27

What is the ability of an object to produce a change in itself or the world around it? - Random

Answer 27

Energy

Question 28

What is rotational motion? -

Answer 28

Rotational motion can be defined as the motion of an object around a circular path, in a fixed orbit.

Question 29

True or False - The work done by friction has a positive value? - Random

Answer 29

False

Question 30

True or False - One way to calculate power is to multiply the force by velocity? - Random

Answer 30

True