Let F = the downstream speed of the water.
<span>Then the boat's upstream speed is: 15 - F </span>
<span>The boat's downstream speed is: 15 + F </span>
<span>Assume both the journeys mentioned take T hours, then using "speed x time = distance" we get: </span>
<span>Downstream journey: (15 + F)T = 140 </span>
<span>Upstream journey: (15 - F)T = 35 </span>
<span>Add the two formulae together: </span>
<span>(15 + F)T + (15 - F)T = 140 + 35 </span>
<span>15T + FT + 15T - FT = 175 </span>
<span>30T = 175 </span>
<span>T = 35/6 </span>
<span>Use one of the equations to find F: </span>
<span>(15 + F)T = 140 </span>
<span>15 + F = 140/T </span>
<span>F = 140/T - 15 </span>
<span>F = 140/(35/6) - 15 </span>
<span>F = 24 - 15 </span>
<span>F = 9 </span>
<span>i.e. the downstream speed of the water is 9 kph </span>
<span>Therefore, the boat's speed downstream is 15 + F = 15 + 9 = 24 kph.
the answer is: *24kph*</span>
Is the velocity constant? Is there any friction?
3 meters per second
then after 40 seconds it must 3*40 = 120 meters
120 meters or 0.12 km if you will
Answer:
966 mph
Explanation:
Using as convention:
- East --> positive x-direction
- North --> Positive y-direction
The x- and y- components of the initial velocity of the jet can be written as
While the components of the velocity of the wind are
So the components of the resultant velocity of the jet are
And the new speed is the magnitude of the resultant velocity:
Answer:
x = 0.4 m
Explanation:
When a spring is stretched from its equilibrium position. Some energy is stored in the spring. This energy is called the elastic potential energy of the spring. The formula used to calculate the magnitude of this stored energy is given as follows:
P.E = (1/2)kx²
where,
P.E = Elastic Potential Energy Stored in the spring = 45 J
k = Spring Constant = 540 N/m
x = amount of stretching = ?
Therefore,
45 J = (1/2)(540 N/m)x²
x² = (45 J)(2)/(540 N/m)
x = √(0.167 m²)
<u>x = 0.4 m</u>
