QuestIuI(2 PUMILS) How much power is needed to lift a 750 kg elephant 14.3 m in 30.0 seconds?
Mass of elephant = m = 750 kg
Height = h = 14.3 m
time = t = 30 seconds
Power needed to lift elephant = P = ?
Power needed to lift elephant ≈ 3507 watts
As we know power is given by
P = PE/t
Where PE is the potential energy and t is the time
Potential energy is given by
PE = mgh
Where m is the mass of elephant, g is the gravitational acceleration and h is the height to lift the elephant.
PE = 750*9.81*14.3
PE = 105212.25 Joules
Therefore, the required power to lift the elephant is
P = PE/t
P = 105212.25/30
P ≈ 3507 watts
A trombone can produce pitches ranging from 85 Hz to 660 Hz approximately. When the trombone is producing a 357 Hz tone, what is the wavelength of that tone in air at standard conditions?
The wavelength of that tone in air at standard condition is 0.96 m.
Given that, a trombone can produce pitches ranging from 85 Hz to 660 Hz approximately. We need to find the wavelength of that tone in air when the trombone is producing a 357 Hz tone.
We know that the speed of sound in air is approximately 343 m/s. Speed of a wave is given by :
So, the wavelength of that tone in air at standard condition is 0.96 m. Hence, this is the required solution.
Which of the following types of waves is not part of the electromagnetic spectrum? A) microwaves B) gamma rays C) ultraviolet radiation D) radio waves E) sound waves
Answer: Sound Waves
Sound waves are the only waves on this list that are not part of the electromagnetic spectrum. This is because sound waves require a medium to travel (molecules to transmit the sound waves), while waves on the electromagnetic spectrum do not require a medium. They are able to travel through space for example, while sound would not be able to.
Sound waves (E) are not electromagnetic at all.
Microwaves, gamma rays, ultraviolet waves, and radio waves all are.
The main force(s) acting on the puck after receiving the kick is (are):_________.A) a downward force of gravity and an upward force exerted by the surfaceB) a downward force of gravity, and a horizontal force in the direction of motionC) a downward force of gravity, an upward force exerted by the surface, and a horizontal force in the direction of motionD) a downward force of gravityA) a downward force of gravity and an upward force exerted by the surface
the statements, the correct one is A
a downward force of gravity and an upward force exerted by the surface
When the disc is hit, a thrust force is exerted in the direction of movement, at the moment the disc moves this force loses contact and becomes zero.
When the movement is already established there are two main forces: gravity that acts downwards and the reaction force to the support of the disk called normal that acts upwards.
As it is not mentioned that there is friction, this force that opposes the movement is zero.
Analyzing the statements, the correct one is A
When the sum of all the forces acting on a block on an inclined plane is zero, the blockA) must be at rest B) must be accelerating C) may be slowing down D) may be moving at constant speed
hmmm thats too hard for me.
If a small child swallowed a safety pin, whywould an X-ray photograph clearly show the location of the pin?
it is in the body system
it would show clearly because it is a metal piece in the body.