Answer:
3. both are true.
Explanation:
Energy increses with decrease in wavelenght.
For photoemission to occur, a threshold energy barrier must be broken.
Higher energy means more electrons will be emmited.
The electrons emmited will posses energy that is less than the incident energy by the value of the threshold energy.
So the higher the energy, the higher the energy possessed by the electrons.
Answer:
Part a)

Part b)

Explanation:
As we know that mountain climber is at rest so net force on it must be zero
So we will have force balance in X direction


now we will have force balance in Y direction


Part a)
so from above equations we have



Part b)
Now for tension in right string we will have


Answer: 900
Explanation: Force equals mass x acceleration F=M×A
Answer:
8. acceleration =
= 1 unit .
9. acceleration =
= -1 unit.
10. acceleration =
= 0 units.
Explanation:
8. i) acceleration = velocity / time
ii) In this figure velocity = time
iii) therefore acceleration =
= 1 unit .
9. i) acceleration = velocity / time
ii) In this figure 4 = m + 5, therefore m = -1
therefore velocity = (-0.5
time) + 5
iii) therefore acceleration =
= -1 units.
10.) velocity is constant at 2
therefore acceleration =
= 0 units