This is not as simple as it looks.
His average speed is NOT (10km/hr + 50km/hr)/2 = 30 km/hr.
You have to use the definition of speed:
Speed = (total distance covered) / (time to cover the distance).
Let's say the distance up (and down) the hill is 'd' .
Then the time it takes to go up the hill is (d/10) hours.
And the time it takes to come down the hill is (d/50) hours.
Total distance = 2d km
Total time = (d/10) + (d/50) = (5d/50) + (d/50) = 6d/50
Speed = distance/time = 2d/(6d/50) = 100d/6d
<em>Speed = </em>100/6 = <em>16-2/3 km/hr</em>
Answer:
Efficiency = 52%
Explanation:
Given:
First stage
heat absorbed, Q₁ at temperature T₁ = 500 K
Heat released, Q₂ at temperature T₂ = 430 K
and the work done is W₁
Second stage
Heat released, Q₂ at temperature T₂ = 430 K
Heat released, Q₃ at temperature T₃ = 240 K
and the work done is W₂
Total work done, W = W₁ + W₂
Now,
The efficiency is given as:
or
Work done = change in heat
thus,
W₁ = Q₁ - Q₂
W₂ = Q₂ - Q₃
Thus,
or
or
also,
or
thus,
thus,
or
or
Efficiency = 52%
The snail’s speed is 0.001042. Hope this helps!
Answer:
Milk.
Explanation:
Density is used to describe how much space an object or substance takes up in relation to the amount of matter in that object or substance (its mass).
Another way to put it is that, density of a substance is the amount of mass of that substance per unit volume. If an object is heavy and compact, it has a high density.
Density = mass/volume
So,
Milk = 1.035 g of milk per 1 ml
Olive oil = 0.85 g of olive oil in 1 ml.
Therefore, milk has a higher mass.
