3 years ago

A stone is dropped from a 80m bridge. How long does it take to fall?

Physics

1 answer:

alexandr402 [8]3 years ago

7 0

Using equation you can solve

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Constant Acceleration Kinematics: Car A is traveling at 22.0 m/s and car B at 29.0 m/s. Car A is 300 m behind car B when the dri

Ainat [17]

Answer:

The taken is $t_A = 19.0 \ s$

Explanation:

Frm the question we are told that

The speed of car A is $v_A = 22 \ m/s$

The speed of car B is $v_B = 29.0 \ m/s$

The distance of car B from A is $d = 300 \ m$

The acceleration of car A is $a_A = 2.40 \ m/s^2$

For A to overtake B

The distance traveled by car B = The distance traveled by car A - 300m

Now the this distance traveled by car B before it is overtaken by A is

$d = v_B * t_A$

Where $t_B$ is the time taken by car B

Now this can also be represented as using equation of motion as

$d = v_A t_A + \frac{1}{2}a_A t_A^2 - 300$

Now substituting values

$d = 22t_A + \frac{1}{2} (2.40)^2 t_A^2 - 300$

Equating the both d

$v_B * t_A = 22t_A + \frac{1}{2} (2.40)^2 t_A^2 - 300$

substituting values

$29 * t_A = 22t_A + \frac{1}{2} (2.40)^2 t_A^2 - 300$

$7 t_A = \frac{1}{2} (2.40)^2 t_A^2 - 300$

$7 t_A =1.2 t_A^2 - 300$

$1.2 t_A^2 - 7 t_A - 300 = 0$

Solving this using quadratic formula we have that

$t_A = 19.0 \ s$

7 0

3 years ago

A 4kg bird is flying with a velocity of 4 m/s. What is its kinetic energy?

Yanka [14]

Kinetic energy = 32 J

8 0

3 years ago

A projectile is launched with an initial velocity of 25m/s at 35 degrees above the horizontal. assuming that the projectile retu

Dovator [93]

Speed is the same as the initial: 25m/s.

*if* you need vectors though:

final velocity = (25*cos(35), -25*sin(35) ) m/s

3 0

3 years ago

Wha is the frequency of a wave having a period equal to 18 seconds?

Rainbow [258]

Answer:

5.5 × 10-2 hertz

Explanation:

The time taken by a wave crest to travel a distance equal to the length of wave is known as wave period.

= 0.055 per second (1 cycle per second = 1 Hertz)

Thus, we can conclude that the frequency of the wave is 5.5 X 10^{-2} hertz.

Hopes this helps, love <3

5 0

3 years ago

Give me 3 events of matter and energy that you can't explain yourself ( need some ideas)

nalin [4]

Answer:

Plasma, Supersolid, Superfluid

Explanation:

I don't know if this is what you are looking for, but I have no idea what these even are.

8 0

3 years ago