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2 years ago

If a car goes down Lake at 30 miles per hour how far will it go in 0.25 hours?

Physics

1 answer:

kati45 [8]2 years ago

7 0

Answer:

7.5 miles

Explanation:

0.25 hours=15minutes.

So you do

30 miles=60minutes

x =15minutes

cross multiply

Ans-7.5

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Un soldado de 1.80 m de altura ha sido herido por una bala, cuya masa es de 100 g. Deciden colocar al soldado en una centrifugad

maks197457 [2]

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3 years ago

An electric toy with a resistance of 2.50 Ω is operated by a 3.00-V battery. (a) What current does the toy draw? (b) Assuming th

Leno4ka [110]

Answer:

a) The current is i = 1.2 A

b) The charge is Q = 17280 C

c) The energy is E = 43200 J

Explanation:

a) The current is given by the ohm's law wich is:

i = V/R = 3/2.5 = 1.2 A

b) Since the charge is steady we can use the following equation to find the charge amount in that time:

i = Q/t

Q = t*i

Where t is in seconds, so we have 4h * 3600 = 14400 s

Q = 1.2*14400 = 17280 C

c) The energy is the power delivered to the toy multiplied by the time:

P = 1.2*2.5 = 3 W

E = P*t = 3*14400 = 43200 J

7 0

2 years ago

Under ideal conditions (no atmospheric interference of any kind), if I hit a golf ball at an angle of 25 degrees at an initial s

g100num [7]

Answer:

The required angle is (90-25)° = 65°

Explanation:

The given motion is an example of projectile motion.

Let 'v' be the initial velocity and '∅' be the angle of projection.

Let 't' be the time taken for complete motion.

Let 'g' be the acceleration due to gravity

Taking components of velocity in horizontal(x) and vertical(y) direction.

$v_{x}$ = v cos(∅)

$v_{y}$ = v sin(∅)

We know that for a projectile motion,

t = $\frac{2vsin(∅)}{g}$

Since there is no force acting on the golf ball in horizonal direction.

Total distance(d) covered in horizontal direction is -

d = $v_{x}$ ×t = vcos(∅)× $\frac{2vsin(∅)}{g}$ = $\frac{v^{2}sin(2∅) }{g}$ .

If the golf ball has to travel the same distance 'd' for same initital velocity v = 23m/s , then the above equation should have 2 solutions of initial angle 'α' and 'β' such that -

α +β = 90° as-

d = $\frac{v^{2}sin(2α) }{g}$ = $\frac{v^{2}sin(2[90-β]) }{g}$ = $\frac{v^{2}sin(180-2β) }{g}$ = $\frac{v^{2}sin(2β) }{g}$ .

∴ For the initial angles 'α' or 'β' , total horizontal distance 'd' travelled remains the same.

∴ If α = 25° , then

β = 90-25 = 65°

∴ The required angle is 65°.

5 0

2 years ago

Read 2 more answers

A solar cooker, really a concave mirror pointed at the Sun, focuses the Sun's rays 13.8 cm in front of the mirror. Part A What i

shepuryov [24]

From the concept of optics on a curvature of a spherical mirror, the proportion for which the focal length is equivalent to half the radius of curvature is fulfilled. Mathematically this is

$f = \frac{R}{2}$

Here,

f = Focal Length

R = Radius

Rearranging to find the radius we have,

$R = 2f$

Replacing with our values,

R = 2(13.8cm)

R = 27.6cm

Therefore the radius of the spherical surface from which the mirror was made is 27.6cm

6 0

2 years ago

3 Points

AleksAgata [21]

Answer:

B.C. D. G.

Explanation:

A vector quantity, has both magnitude and direction. A tip to remember is if you can add a direction to it! You wouldnt say 30 pounds north, but you would say 30 mph north.

<em>I hope this helped! Comment if you have any questions! :)</em>

3 0

2 years ago