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AnnZ [28]
2 years ago
5

A 0.14-km wide river flows with a uniform speed of 4.0 m/s toward the east. It takes 20 s for a boat to cross the river to a poi

nt directly north of its departure point on the south bank. What is the speed of the boat relative to the water
Physics
1 answer:
Dmitry [639]2 years ago
7 0

Answer:

The right approach is "8.1 m/s". A further explanation is provided below.

Explanation:

According to the table,

Speed of Boat

= \frac{s}{t}

V_b=\frac{140}{20}

V_a = 4 \ m/s

V_B = 7 \ m/s

Now,

⇒  (V_{relative})^2 = (7)^2+(4)^2

or,

⇒  (V_r)^2=49+16

              =65

         V_r=\sqrt{65}

              =8.1 \ m/s

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A glass capillary tube with a diameter of 8.5 mm and length 8 cm is filled with a salt solution with a resistivity of 2.5 ?m. Wh
MA_775_DIABLO [31]

Answer:

The resistance is 3.5\times10^{-4}\ \Omega

Explanation:

Given that,

Diameter of tube = 8.5 mm

Length = 8 cm

Resistivity = 2.5 m

We need to calculate the resistance

The resistance is equal to the product of the resistivity and length divided by the area of cross section .

In mathematical form,

R = \dfrac{\rho\times l}{A}

Where, \rho=resistivity

l = length

A = area of cross section

Put the value into the formula

R = \dfrac{2.5\times8\times10^{-2}}{3.14\times(\dfrac{8.5}{2}\times10^{-3})^2}

R=3526.32\ \Omega

R=3.5\times10^{-4}\ \Omega

Hence, The resistance is 3.5\times10^{-4}\ \Omega

6 0
3 years ago
During a circus act, an elderly performer thrills the crowd by catching a cannon ball shot at him. The cannon ball has a mass of
Ipatiy [6.2K]

Answer:

m v1 = (m + M) v2

v2 = m v1 / (m + M)

v2 = 7 * 74 / (74 + 65)

3.73 m/s

74 kg is too heavy for the cannonball (over 150 lbs)

4 0
2 years ago
Can you label the parts of the eye?
photoshop1234 [79]

Answer:

  1. Iris
  2. Pupil
  3. Corona
  4. Anterior chamber
  5. lens
  6. Vitreous humor
  7. Blood vessels
  8. Optic nerve
  9. Hyaloid canal
  10. Retina

Hope it helps :)

7 0
2 years ago
Two positive charges of same magnitude are separated by some distance if we bring a unit positive charge from one charge to anot
Studentka2010 [4]

Answer:

Increases.

Explanation:

The electric potential increases when the two positive charges of same magnitude bring close to one charge to another because there is repulsive force between them due to same charge and when the two opposite charges move away from each other, the potential energy decreases. When two opposite charges are brought closer together, electric potential energy decreases while on the other hand, when we move opposite charges apart from each other than the work done against the attractive force that leads to an increase in electric potential energy.

3 0
2 years ago
In springboard diving, the diver strides out to the end of the board, takes a jump onto its end, and uses the resultant spring-l
Ksenya-84 [330]

Answer:

10.4 m/s

Explanation:

The problem can be solved by using the following SUVAT equation:

v=u+at

where

v is the final velocity

u is the initial velocity

a is the acceleration

t is the time

For the diver in the problem, we have:

u=+6.3 m/s is the initial velocity (positive because it is upward)

a=g=-9.8 m/s^2 is the acceleration of gravity (negative because it is downward)

By substituting t = 1.7 s, we find the velocity when the diver reaches the water:

v=+6.3 + (-9.8)(1.7)=-10.4 m/s

And the negative sign means that the direction is downward: so, the speed is 10.4 m/s.

3 0
3 years ago
Read 2 more answers
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