How long does it take a car to cross a 20m bridge if it starts from rest and accelerates at 5 m/s^2?

hello friends,i need your help my home work now in physics,topic:motion.40 marks +brainliest if correct .

fenix001 [56]

Answer:

See below

Explanation:

Vertical position is given by

df = do + vo t - 1/2 a t^2 df = final position = 0 (on the ground)

do =original position = 2 m

vo = original VERTICAL velocity = 0

a = acceleration of gravity = 9.81 m/s^2

THIS BECOMES

0 = 2 + 0 * t - 1/2 ( 9.81)t^2

to show t = .639 seconds to hit the ground

During this .639 seconds it flies horizontally at 10 m/s for a distance of

10 m/s * .639 s = 6.39 m

5 0

1 year ago

If a 400-mm diameter pipe with a pipe roughness coefficient of 100 flows full of pressurized water with a head loss of 0.4 ft pe

RoseWind [281]

Answer:

Q = 913.9 gpm

Explanation:

The Hazen Williams equation can be written as follows:

$P = \frac{4.52\ Q^{1.85}}{C^{1.85}d^{4.87}}$

where,

P = Friction Loss per foot of pipe = $\frac{0.4}{1000\ ft}$ = 4 x 10⁻⁴

Q = Flow Rate in gallon/min (gpm) = ?

d = pipe diameter in inches = (400 mm)(0.0393701 in/1 mm) = 15.75 in

C = roughness coefficient = 100

Therefore,

$4\ x \ 10^{-4} = \frac{4.52\ Q^{1.85}}{(100)^{1.85}(15.75)^{4.87}}\\\\Q^{1.85} = \frac{4\ x \ 10^{-4}}{1.33\ x\ 10^{-9}} \\\\Q = (300384.75)^\frac{1}{1.85}$

Q = 913.9 gpm

5 0

3 years ago

In the circuit diagram, what does the symbol made of two long lines and two short lines with a positive and a negative sign at e

Tom [10]

For those seeking for the answer, its a source of electrical energy.

8 0

3 years ago

Read 2 more answers

An object of mass 800g hangs on a spring. Calculate the force exerted by the object if acceleration due to gravity is 10/s2

xxTIMURxx [149]

Answer:

8 N

Explanation:

Using the equation F=ma (F: force/ m: mass in kg/ a: acceleration),

F = (800/1000)(10)

F = 8 N

4 0

3 years ago

A skater slides across the ice with an initial velocity of 5.0 m/s. She slows 10 points

zvonat [6]

Explanation:

Given that,

The initial velocity of a skater is, u = 5 m/s

She slows to a velocity of 2 m/s over a distance of 20 m.

We can find the acceleration of skater. It is equal to the rate of change of velocity. So, it can be calculated using third equation of motion as follows :

$v^2-u^2=2as$

a = acceleration

$a=\dfrac{v^2-u^2}{2s}\\\\a=\dfrac{(2)^2-(5)^2}{2\times 20}\\\\a=-0.525\ m/s^2$

So, her acceleration is $0.525\ m/s^2$ and she is deaccelerating. Also, her initial velocity is given i.e. 5 m/s.

7 0

3 years ago