m = Mass of the refrigerator to be moved to third floor = 136 kg
g = Acceleration due to gravity by earth on the refrigerator being moved = 9.8 m/s²
h = Height to which the refrigerator is moved = 8 m
W = Work done in lifting the object
Work done in lifting the object is same as the gravitational potential energy gained by the refrigerator. hence
Work done = Gravitation potential energy of refrigerator
W = m g h
inserting the values
W = (136) (9.8) (8)
W = 10662.4 J
As we know that acceleration is directly proportional to force, therefore as the force is doubled, acceleration gets doubled too.
Answer:
θ= 5 radian
Explanation:
Given data:
Radius r = 0.70 m
Initial angular speed ω_i = 2rev/s
Time t = 5 s
Final angular speed ω_f =0
so we have angular displacement

putting values
= 5 rad
Answer:
agree with student 2, disagree with student 1
Explanation:
If you want to know if the wavelength of light was shifted you have to know the original wavelengths
Since we know the absorption spectrum for elements like hydrogen, we can look for these absorption lines in the star's spectra and figure out what direction these lines are shifted and tell if the star is moving away or towards us
The color of the star refers to the temperature of the star's surface which is not related to the doppler shift of the star
Answer:
No
Explanation:
For infinite speed to be achevied, one must have no sink of energy to spend. The source of entropy in this example, is the tires hitting the surface, producing heat and friction. Not to mention that you'd still need fuel to start the car, and an infinite tunnel or track, which would be impossible and speed up to process of energy loss through entropy quicker.