Answer:
Average force = 67 mn
Explanation:
Given:
Initial velocity u = 0 m/s
Final velocity v = 67 m/s
Time t = 1 ms = 0.001 sec.
Computation:
Using Momentum theory
Change in momentum = F × Δt
(v-u)/t = F × Δt
F × 0.001 = (67 - 0)/0.001
F= 67,000,000
Average force = 67 mn
The average power is 10 watts. What's the question ?
<span>The four goals of psychology are: describe observed phenomena, explain them, predict what may occur as a result of them and control behaviour as a result. Julie’s psychologist has helped Julie control her behaviour - her fear response to spiders - so they have met the ‘control behaviour’ goal of psychology.</span>
Well, the acceleration is the difference of speeds divided by the time period.

.
One rev/s is

, so our final result is

.
Answer: f = - 0.50 m, negative (diverging) lens
Explanation: D-value (diopter ) means 1/f, unit is 1/m. Thus -2.0D
Means f = ( 1/ -2.0 ) m = -0.50 m