In this item, we let x be the rate of the boat in still water and y be the rate of the current.
Upstream. When the boat is going upstream, the speed in still water is deducted by the speed of the current because the boat goes against the water. The distance covered is calculated by multiplying the number of hours and the speed.
(x - y)(3) = 144
Downstream. The speed of the boat going downstream is equal to x + y because the boat goes with the current.
(x + y)(2) = 144
The system of linear equations we can use to solve for x is,
3x - 3y = 144
2x + 2y = 144
We use either elimination or substitution.
We solve for the y of the first equation in terms of x,
y = -(144 - 3x)/3
Substitute this to the second equation,
2x + 2(-1)(144 - 3x)/3 = 144
The value of x from the equation is 60
<em>ANSWER: 60 km/h</em>
Aw don’t say that! I’m sure your beautiful:)
Answer:
= 1000 hours
Explanation:
Earth's circumference is 10⁴ mile
speed of a sailboat is 10¹ mile/hour
distance = speed × time
10⁴ = 10¹ × t
t = 10⁴ / 10¹
t = 10³
= 1000 hours
Answer:
v = 21.25 km/h
The average velocity is 21.25km/h
Explanation:
Average velocity = total displacement/time taken
v = d/t
Given;
A car travels 50 km in 25 km /h
d1 = 50km
v1 = 25km/h
time taken = distance/velocity
t1 = d1/v1
t1 = 50/25 = 2 hours
and then travels 60km with a velocity 20 km/h
d2 = 60km
v2 = 20km/h
t2 = d2/v2 = 60/20
t2 = 3 hours
and then travels 60km with a velocity 20 km/h in the same direction
d3 = 60km
v3 = 20km/h
t3 = d3/v3 = 60/20
t3 = 3 hours
Average velocity = total displacement/total time taken
v = (d1+d2+d3)/(t1+t2+t3)
v = (50+60+60)/(2+3+3)
v = 170/8
v = 21.25 km/h
The average velocity is 21.25km/h
Answer: 14.1 m/s
Explanation:
We can solve this with the Conservation of Linear Momentum principle, which states the initial momentum 
(before the elastic collision) must be equal to the final momentum 
(after the elastic collision):
(1)
Being:
Where:
is the combined mass of Tubby and Libby with the car
is the velocity of Tubby and Libby with the car before the collision
is the combined mass of Flubby with its car
is the velocity of Flubby with the car before the collision
is the velocity of Tubby and Libby with the car after the collision
is the velocity of Flubby with the car after the collision
So, we have the following:
(2)
Finding :
(3)
(4)
Finally:
