Alex Gruest, Diego Gomez, Juan Muñoz - Gravitational Motion, Rotational Motion, Work, Energy Flashcards
What is work? - Remember
Work is equal to the product of the magnitude of the force and magnitude of displacement times the cosine of the angle between them.
What is the definition of energy? - Remember
It´s the capacity for doing work.
Can energy be lost? - Remember
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
What is motion? - Remember
Motion is the change with time of the position or orientation of a body.
What is gravitational motion - Remember
The natural phenomenon of attraction between physical objects with mass or energy.
What is the equation of work? - Identify
W = fd , FORCE * DISTANCE
What equation is used in order to find the Average Angular Velocity of an object? - identify
The angular velocity equals the angular displacement divided by the time required to make the rotation.
What is power? - Identify
Power is the amount of energy transferred or converted per unit of time.
What is the equation for Power? - Identify
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.
What is the unit of torque? - Identify
Nm, which is Newton Meters
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
W = 6.93 * 10 (to the power of 3) J
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
The rotational acceleration is 0.21 rad/s^2
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
It should be placed at 61.7 m.
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
The work done is 1,470 J.
How much gravitational potential energy does a 75 kg diver have stepping off the edge of a 5 m platform? - Calculate
The diver is making 3,675 J.
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
W = Fd cos o
= (4.50 N) (0.150 M) (cos 0 )
= 0.675 J
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
= 0.0 J * 1.6*10(power 3) J - 0.0 J
= 1.6 * 10(power 3) J
b. What is the limb’s speed when it reaches the roof? (Use info of past flashcard) - Understand
= 12 m/s
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
P = w/t
= Fd/t
= (1.20 * 10(power 4) N)(9.00 M) / (15.0 s)
= 7.20 kW
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
W = Fd cos 0
= (255 N)(30.0 M)(cos 25.0)
= 6.93 * 10 (to the power of 3) J
You are jumping on a trampoline. When you are at highest point in the air, what kind of energy is that? - Random
Is Potential Energy.
Work is a measurement of how much force is applied over a certain … ? - Random
… Distance
Both work and energy are measured in … ? - Random
Joules, both are measured in Joules.
As an object’s mass increases, its gravitational pull will … ? - Random
Increase, the gravitational pull increases
What is gravitational rotation? - Remember
Rotational gravity, is thus the appearance of a centrifugal force in a rotating frame of reference
What is gravitational motion? - Remember
It´s the force of attraction that bodies exert on one another as a result of their mass.
What is the ability of an object to produce a change in itself or the world around it? - Random
Energy
What is rotational motion? -
Rotational motion can be defined as the motion of an object around a circular path, in a fixed orbit.
True or False - The work done by friction has a positive value? - Random
False
True or False - One way to calculate power is to multiply the force by velocity? - Random
True
