1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
vesna_86 [32]
3 years ago
12

A river flows at a velocity of 3 km/h relative to the riverbank. A boat moves downstream at a velocity of 15 km/h relative to th

e river. What is the velocity of the boat relative to the riverbank?
Physics
1 answer:
Alexus [3.1K]3 years ago
3 0
15+3=18km/hour
Think about it like this. The boat is going 15 faster than the river, and the river is going 3 faster than the bank, so the boat is going 18 faster than the river bank
You might be interested in
What are the equations of angular acceleration, angular velocity and theta?.
soldier1979 [14.2K]
Θ is the angular displacement = ωt
ω is the angular velocity = θ/t
α is the angular acceleration = ω/t
3 0
3 years ago
From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 121.6 nanome
lina2011 [118]

Answer:

b) The star is moving away from us.

Explanation:

If an object moves toward us, the light waves it emits are compressed - the wavelength of the light will be shorter, making the light bluer. On the other hand, if an object moves away from us, the light waves are stretched, making it redder. If from laboratory measurements we know that a specific hydrogen spectral line appears at the wavelength of 121.6 nanometers (nm) and the spectrum of a particular star shows the same hydrogen line appearing at the wavelength of 121.8 nm, we can conclude that the star is moving away from npos, since the wavelength related to that star is more expanded.

7 0
3 years ago
Which of the following is not a part of the modern theory of evolution?
telo118 [61]

Answer:

D

Explanation:

D) Evolution proceeds in the direction desired by members of a generation is not the modern theory of evolution.

Evolution can not proceed in the direction as desire by the members of the generation as No matter how hard you and your friends wish that your children will be born with the ability to fly unassisted, the kids will have to use airlines like the rest of us. All the rest of these contribute to evolution

5 0
3 years ago
At an air show, a stunt pilot performs a vertical loop-the-loop in a circle of radius 3.63 x 103 m. During this performance the
san4es73 [151]

Answer:

189 m/s

Explanation:

The pilot will experience weightlessness when the centrifugal force, F equals his weight, W.

So, F = W

mv²/r = mg

v² = gr

v = √gr where  v = velocity, g = acceleration due to gravity = 9.8 m/s² and r = radius of loop = 3.63 × 10³ m

So, v = √gr

v = √(9.8 m/s² × 3.63 × 10³ m)

v = √(35.574 × 10³ m²/s²)

v = √(3.5574 × 10⁴ m²/s²)

v = 1.89 × 10² m/s

v = 189 m/s

5 0
3 years ago
Why is the moon’s surface cratered, but the Earth’s is not
Scorpion4ik [409]

The comets hit the moon's surface because there is no atmosphere on the moon to protect it. The earth has an atmosphere so it is protected.

8 0
3 years ago
Other questions:
  • Since astronauts in orbit are apparently weightless, a clever method of measuring their masses is needed to monitor their mass g
    12·1 answer
  • Which one of the following temperatures is equal to 5°C?
    13·2 answers
  • When a brick is dropped from the roof of a house, it lands on the ground with a speed v. What will the speed at ground level be
    7·1 answer
  • Suzanne makes a tower out of six identical plastic box. Then she uses a pan balance to measure the mass of the tower. She finds
    15·2 answers
  • On the moon, what would be the force of gravity acting on an object that has a mass of 7 kg?
    9·1 answer
  • Light traveling through air encounter a second medium which slows the light to 2.7 x 10^8. What is the index of the medium?
    13·1 answer
  • A SMALL cup of tea has water inside that is very hot, about 80 degrees Celsius. A LARGE bathtub has water inside it that is warm
    7·1 answer
  • When an object absorbs light energy, it reflects
    5·1 answer
  • Question 2 10
    5·1 answer
  • Copper wire is 1. 9 mm in diameter and carries a current of 20 a. What is the electric field stregnth inside this wire?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!