D = distance between the cars at the start of time = 680 km
v₁ = speed of one car
v₂ = speed of other car = v₁ - 10
t = time taken to meet = 4 h
distance traveled by one car in time "t" + distance traveled by other car in time "t" = D
v₁ t + v₂ t = D
(v₁ + v₂) t = D
inserting the values
(v₁ + v₁ - 10) (4) = 680
v₁ = 90 km/h
rate of slower car is given as
v₂ = v₁ - 10
v₂ = 90 - 10 = 80 km/h
Formulas change from F to degree C : C = ( F - 32 )/1.8
so we have (77-32)/1.8 = 25 oC
ok done. Thank to me :>
Answer:
The answer is D. density.
The answer is A) velocity, because velocity is speed and displacement.
Hope this helps
