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3 years ago

A vector starts at the point (0.0) and ends at (2,-7) what is the magnitude of the displacement

Physics

1 answer:

Leto [7]3 years ago

5 0

Answer:

|x| = √53

Explanation:

We are told that the vector starts at the point (0.0) and ends at (2,-7) .

Thus, magnitude of displacement is;

|x| = √(((-7) - 0)² + (2 - 0)²)

|x| = √(49 + 4)

|x| = √53

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A car traveling west in a straight line on a highway decreases its speed from 30.0 meters per second to 23.0 meters per second i

pychu [463]

Acceleration, a = (v - u) / t

Initial Velocity, u = 30 m/s
Final Velocity, v = 23 m/s
time t = 2.00 seconds

a = (23 - 30) / 2
a = -7 / 2 = -3.5 m/s2

So the acceleration is negative, which means it is a deceleration of 3.5 m/s2.

8 0

3 years ago

Where is the near point of an normal eye when accidentally wear a contact lens with a power of +2.0 diopters?

Lerok [7]

Answer:

The near point of an eye with power of +2 dopters, u' = - 50 cm

Given:

Power of a contact lens, P = +2.0 diopters

Solution:

To calculate the near point, we need to find the focal length of the lens which is given by:

Power, P = $\frac{1}{f}$

where

f = focal length

Thus

f = $\frac{1}{P}$

f = $\frac{1}{2}$ = + 0.5 m

The near point of the eye is the point distant such that the image formed at this point can be seen clearly by the eye.

Now, by using lens maker formula:

$\frac{1}{f} = \frac{1}{u} + \frac{1}{u'}$

where

u = object distance = 25 cm = 0.25 m = near point of a normal eye

u' = image distance

Now,

$\frac{1}{u'} = \frac{1}{f} - \frac{1}{u}$

$\frac{1}{u'} = \frac{1}{0.5} - \frac{1}{0.25}$

$\frac{1}{u'} = \frac{1}{f} - \frac{1}{u}$

Solving the above eqn, we get:

u' = - 0.5 m = - 50 cm

7 0

3 years ago

I'm very confused. Thanks for whoever helps me :)

sergij07 [2.7K]

(C). Remember gravity provides an acceleration of 9.81m/s^2, so the y component of velocity initial is zero because it isn’t already falling, and we have the height, so basically we use the kinematic equation vf^2=vi^2+2ad, substitute given values and you get vf^2=2(9.81)(65) which is 1275, when you take the square root you get 35.7m/s for final velocity
(B). Then you use vf=vi+at to get the equation 35.7=(9.81)t, when you divide out you get 3.64s for time t
(A). Finally, since we assume that there is no acceleration or deceleration horizonatally, we just multiply the time taken for it to hit the ground and the initial speed ((3.64)(35.7)) to get 129.96, with significant figures I would round that to 130 metres.
**this is in the order that I felt was easiest to answer**

6 0

3 years ago

If you are driving 100 km/h along a straight road and you look to the side for 1.6 s , how far do you travel during this inatten

denis23 [38]

Answer:

The distance traveled is 44.45 m

Solution:

As per the question:

Average speed, $\bar{v} = 100\ km/h$