Answer:
He travel for 2 h at the first part and 2 h for the second part.
Explanation:
given information:
business trip's distance, = 214 miles
v₁ = 53 mph
v₂ = 54 mph
t₁ = t
t₂ = 4 - t
now lets find the distance of each speed
s₁ = v₁ t₁ = 53 t₁
s₂ = v₂ t₂ = 54 t₂
= s₁ + s₂
214 = 53 t₁ + 54 t₂
214 = 53t + 54 (4-t)
214 = 53t + 216 - 54 t
t = 216 - 214
= 2 h
t₁ = t = 2 h
t₂ = 4 - t = 4 -2 = 2h
Answer:
B
Explanation:
This looks like a momentum question. It also looks like there is no horizontal acceleration.
Momentum before Momentum after
m1vo (m1 + m2)*vo/3 multiply through by 3
3 m1*vo m1* vo + m2*vo subtract m1*vo from both sides
3m1*vo - m1*vo m2*vo
2m1*vo m2*vo Divide by vo
2m1 = m2
Conclusion: It takes 2 m1's to equal 1 m2.
B is the answer.
Black peppered moths had adapted to camoflage into their surroundings. Seeing as there was more pollution during the industrial revolution that made trees etc darker, the moths could camoflage more easily than other coloured moths who would have been more obvious to predators. These moths survived whereas the others did not. The surviving moths bred with other peppered moths to reproduce even more peppered moths who also survived.