Answer:
Ff = 19.6 N
Explanation:
So since its saying whats the minimum F to move the block, we will use static friction (0.5).
We will use the equation for force of friction, which is Ff = uFn
Ff = (0.5)(4)(9.8)
Ff = 19.6 N
this is the minumum force needed to move the block, as that is the frictional force. You would need to apply a minimum force of 19.6 N to move the block
Answer:
(a) The energy of the photon is 1.632 x 
J.
(b) The wavelength of the photon is 1.2 x 
m.
(c) The frequency of the photon is 2.47 x 
Hz.
Explanation:
Let;
= -13.60 ev
= -3.40 ev
(a) Energy of the emitted photon can be determined as;
- = -3.40 - (-13.60)
= -3.40 + 13.60
= 10.20 eV
= 10.20(1.6 x 
)
- = 1.632 x Joules
The energy of the emitted photon is 10.20 eV (or 1.632 x Joules).
(b) The wavelength, λ, can be determined as;
E = (hc)/ λ
where: E is the energy of the photon, h is the Planck's constant (6.6 x 
Js), c is the speed of light (3 x 
m/s) and λ is the wavelength.
10.20(1.6 x ) = (6.6 x * 3 x )/ λ
λ = 
= 1.213 x
Wavelength of the photon is 1.2 x m.
(c) The frequency can be determined by;
E = hf
where f is the frequency of the photon.
1.632 x = 6.6 x x f
f = 
= 2.47 x Hz
Frequency of the emitted photon is 2.47 x Hz.
Answer:
a) 17 km
b) 9 km
Explanation:
The distance is the length of the path.
A to C: 5 km
B to C: 4 km
C to B: 4 km
B to C: 4 km
Total distance = 5 km + 4 km + 4 km + 4 km = 17 km
Displacement is the difference between the starting point and ending point.
Displacement = 9 km − 0 km = 9 km
Energy is calculated as power*time, so give the wattage of 1200 W (equivalent to 1200 Joules/second) and time of 30 seconds, multiplying these gives 36000 J or 36 kJ of electrical energy.
If electrical charge or current is needed: Power = voltage * current, so given the power of 1200 watts and voltage of 120 V, current is 1200 W / 120 V = 10 Amperes. Charge is calculated by multiplying 10 A*30 s = 300 C.
