Kiley went 5.7 km/h north and then went 5.8 km/h west. From start to finish, she went 8.1 km/h northwest.

Physics

2 answers:

cluponka [151]3 years ago

8 0

Explanation :

Instantaneous velocity: It is defined as the velocity at a particular instant of time.

Average velocity is the ratio of total displacement covered by an object divided by the total time taken.

It is given that, Kiley went 5.7 km/h north and then went 5.8 km/h west. Here, both direction as well as magnitude of velocity is given. This implies the instantaneous speeds.

The resultant of these two velocities would be :

$v=\sqrt{ (v_N)^2+(-v_w)^2$

$v=\sqrt{(5.8\ km/h)^2+(5.7\ km/h)^2}$

$v=8.1\ km/h$

She went 8.1 km/h northwards. This implies resultant velocity i.e. average speed.

So, the correct option is (a).

Hence, this is the required solution.

TiliK225 [7]3 years ago

6 0

<span>5.7 km/h north and 5.8 km/h west are instantaneous velocities, while 8.1 km/h is the average velocity.

This is because each value has a magnitude and direction so it is a velocity. Moreover, the 8.1 km/h is the resultant of the two velocities so it is the average while the other two are instantaneous.</span>

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Three point charges are arranged on a line. Charge q3 = 5 nC and is at the origin. Charge q2 = - 3 nC and is at x = 4 cm. Charge

Taya2010 [7]

Answer:

q₁ = + 1.25 nC

Explanation:

Theory of electrical forces

Because the particle q₃ is close to two other electrically charged particles, it will experience two electrical forces and the solution of the problem is of a vector nature.

Known data

q₃=5 nC

q₂=- 3 nC

d₁₃= 2 cm

d₂₃ = 4 cm

Graphic attached

The directions of the individual forces exerted by q1 and q₂ on q₃ are shown in the attached figure.

For the net force on q3 to be zero F₁₃ and F₂₃ must have the same magnitude and opposite direction, So, the charge q₁ must be positive(q₁+).

The force (F₁₃) of q₁ on q₃ is repulsive because the charges have equal signs ,then. F₁₃ is directed to the left (-x).

The force (F₂₃) of q₂ on q₃ is attractive because the charges have opposite signs. F₂₃ is directed to the right (+x)

Calculation of q1

F₁₃ = F₂₃