<span>If the swimmer is swimming perpendicular to the current, it will take her 66m / 0.42 m/s = 157.14 seconds to cross the river. At the same time, the current will be taking her downstream at a rate of 0.32 m/s. So, when she reaches the opposite bank, her total downstream distance traveled will have been 0.32*157.14 = 50.28 meters.</span>
Answer:
Force is 57.69 N to the opposite direction of motion of dolphin.
Explanation:
We have force is the product of mass and acceleration.
That is
Force = Mass x Acceleration
F = ma
Mass of dolphin, m = 30 kg
We have equation of motion, v = u + at
Final velocity, v = 7 m/s
Initial velocity, u = 12 m/s
Time, t = 2.60 s
Substituting
7 = 12 + a x 2.6
a = -1.92 m/s²
Force, F = 30 x -1.92 = -57.69 N
So the force is 57.69 N to the opposite direction of motion of dolphin.
the wavelength is 2.2m
wavelength can be calculated by formula wavelength = velocity / frequency so here first we need to find the velocity so velocity is distance travelled/time taken that 2 X 10^8 m/s now wavelength is = 2 X 10^8/ 90=2.2m.
Waves are signals that can go through various media, including wire in the case of an electrical AC current, water, light, and other media. The separation between two identical points on a sinusoidal wave is known as the wavelength. You can determine how long there is between each wave's peak and each wave's trough if you know the frequency of the wave moving through the medium.
To learn more about wavelength:
brainly.com/question/13533093
#SPJ4
Answer:
29 seconds
Explanation:
First we have a constant speed of 12 m/s and the distance of 240 m, so to find the time we can use the formula:
distance = speed * time
240 = 12 * time1
time1 = 20 seconds
Then, the speed decreases at 2 m/s2 until it reaches 2 m/s. So to find this time, we use this formula:
Final speed = inicial speed + acceleration * time
2 = 12 - 2 * time2
2*time2 = 10
time2 = 5 seconds.
Then, the speed increases from 2 m/s to 22 m/s with an acceleration of 5 m/s2, so we have:
Final speed = inicial speed + acceleration * time
22 = 2 + 5 * time3
5*time3= 20
time3 = 4 seconds
The total time is:
Total time = time1 + time2 + time3 = 20 + 5 + 4 = 29 seconds
