Answer:
FAE= 0.014 N
Explanation:
The KE of block is decreased because of the slowing action of the friction force .
Change in KE of block = work done on block by friction ƒ
⠀ ➪ ½mu²ƒ - ½mu²i = Fƒs cos θ
Because the friction force on the block is opposite in direction to the displacement , cos θ = -1
➢ Using Uƒ = 0 , Vƒ = 0.20 m/s , and s = 0.70 m
✒ We find ,
➪½mu²ƒ - ½mu²i = Fƒs cos θ
➪0-½ (0.50 kg) (0.20 m/s)² = (Fƒ) (0.70 m) (-1)
➪ Fƒ = 0.014 N
Hope this helped, can i pls have brainliest
B. The sound of the engine will get louder and the pitch higher.
Answer:
material work function is 0.956 eV
Explanation:
given data
red wavelength 651 nm
green wavelength 521 nm
photo electrons = 1.50 × maximum kinetic energy
to find out
material work function
solution
we know by Einstein photo electric equation that is
for red light
h ( c / λr ) = Ф + kinetic energy
for green light
h ( c / λg ) = Ф + 1.50 × kinetic energy
now from both equation put kinetic energy from red to green
h ( c / λg ) = Ф + 1.50 × (h ( c / λr ) - Ф)
Ф =( hc / 0.50) × ( 1.50/ λr - 1/ λg)
put all value
Ф =( 6.63 ×
(3 ×
) / 0.50) × ( 1.50/ λr - 1/ λg)
Ф =( 6.63 × (3 × ) / 0.50 ) × ( 1.50/ 651×
- 1/ 521 ×)
Ф = 1.5305 ×
J × ( 1ev / 1.6 × J )
Ф = 0.956 eV
material work function is 0.956 eV
Human error (average human reaction time is .2 seconds)
If you have (1 x 10⁹) cubic meters of volume, and 1/2 gram of mass
in each cubic meter, then you have
(1/2 x 10⁹) grams = (5 x 10⁸) grams = (5 x 10⁵) kilograms of mass .
On Earth, that mass weighs 4,900,000 newtons .
(about 1,102,300 pounds)
(about 551 tons)
