Answer:
Explanation:
Givens
d = 115 km
r = 80 km/hr
t = ?
Equation
d = r*T
Solution
115 = 80 * t Divide by 80
115/80 = t
t = 1.4375 hours.
Friction force is equal to the applied force F until the block starts moving. Hence, it will increase until the maximum value of 3.0*10*0.50=150 N.
While it's moving, the friction will be 3.0*10*0.2 = 60 N, constant. The rest of the applied force will accelerate the block.
Best Answer:<span> </span><span>hf = work function + KE
However if you are looking at the max wavelength (or threshold frequency) then there will only be just enough energy for the photoelectrons to be liberated, hence their KE will be 0.
So hf = work function
convert eV to joules, 2.4 x (1.6 x 10^-19) = 3.84 x 10^-19
therefore, hf = 3.84 x 10^-19
f = 3.84 x 10^-19 / planck's constant which is 6.63 x 10^-34
f = 5.79 x 10^14 Hz
c = frequency x wavelength,
wavelength = speed of light/frequency
= (3x10^8)/(5.79x10^14)
=5.18 x 10^-7 metres</span>
