Among the choices the <span>statements that best explains why the size of the refracting telescope lens is kept small at the cost of reducing its capacity to gather radiations from space is "</span><span>Big lenses do not focus light properly to produce clear images. "</span>
Answer:
Mathematical
Explanation:
The answer mathematical because you comparing the length and width of an average human face. I hope this helps you out.
Answer:
d_t = 3.05km
v_a = 4.3km/h
Explanation:
42mins*(2/3) = 28mins
42mins-28mins = 14mins
d = v*t
d_1 = (4km/h)*(1h/60mins)*(28mins)
d_1 = 1.87km
d_2 = (5km/h)*(1h/60mins)*(14mins)
d_2 = 1.17km
d_t = d_1+d_2
d_t = 1.87km+1.17km
d_t = 3.05km
v_a = (v_1+v_2)/2
v_a = [(2*4km/h)+5km/h)]/3
v_a = 4.3km/h
So the person weighs 65kg, and 9.4% of that is head, so 65*0.094 = 6.11 kg is the mass of the head. If we deaccelerate from 40 m/s to 0 m/s in 0.2 s, our total acceleration is: a = Δv/Δt = (0 - 40)/(0.2 - 0) = -200 m/s². We can then use Newton's second law, F = ma, to find the force, using m as mass of the head and a as our acceleration (we'll ignore the negative sign because we don't care about the force's direction here). F = ma = (6.11)(200) = 1222 N, a pretty large amount of force.
It now occurs to me that the easier way to do this, though slightly more advanced, is to use that Force is the derivative of momentum, or F = dp/dt, or with no calculus, F = Δp/Δt, where p is momentum and t is time. p = mv, where m is mass and v is velocity, so F = Δp/Δt = Δ(mv)/Δt = ((6.11)(0) - (6.11)(40))/(0.2 - 0) = (6.11)(40)/(0.2) = 1222 N. So yeah it's quicker, I feel this is less straight forward though.