Anyone know this? PLEASE HELP, I just want to get this exam finished with ):

Using energy considerations and assuming negligible air resistance, show that a rock thrown from a bridge 23.5 m above water wit

Elodia [21]

As stated in the statement, we will apply energy conservation to solve this problem.

From this concept we know that the kinetic energy gained is equivalent to the potential energy lost and vice versa. Mathematically said equilibrium can be expressed as

$\Delta KE = \Delta PE$

$\frac{1}{2}mv_f^2-\frac{1}{2} mv_0^2 = mgh_2-mgh_1$

Where,

m = mass

$v_{f,i}$ = initial and final velocity

g = Gravity

h = height

As the mass is tHe same and the final height is zero we have that the expression is now:

$\frac{1}{2}v_f^2-\frac{1}{2} v_0^2 = gh_2$

$\frac{1}{2} (v_f^2-v_0^2) = gh_2$

$(v_f^2-v_0^2) = 2gh_2$

$v_f = \sqrt{2gh_2+v_0^2}$

$v_f = \sqrt{2(9.8)(23.5)+13.6^2}$

$v_f = 25.4m/s$

7 0

3 years ago

Energy

Ahat [919]

I think the answer may be D- mechanical

7 0

4 years ago

Read 2 more answers

The total weight of a car with passengers is 30,000N. The area of contact of each of the four tyres with the ground is 0.025m2.

vlabodo [156]

Answer:

<em>The minimum pressure car tire pressure is 300,000 Pa</em>

Explanation:

<u>Pressure</u>

It's a measure of the force exerted by an object per unit surface:

$\displaystyle P=\frac{F}{A}$

Where F is the force applied on a surface area A.

We are given the total weight of a car with passengers as Ft=30,000 N and we also know the area of contact of each tire with the ground as $A=0.025 m^2$ .