All categories

3 years ago

A 50Kg girl jumps off a 5-meter-high diving board. What is her kinetic energy right before she hits the water?

Physics

1 answer:

Kryger [21]3 years ago

6 0

Answer:

2450 J

Explanation:

Given that,

A 50Kg girl jumps off a 5-meter-high diving board.

We need to find the kinetic energy of the girl before she hits the water. At this point the kinetic energy becomes equal to the potential energy such that,

$K=mgh\\\\K=50\times 9.8\times 5\\\\K=2450\ J$

So, her kinetic energy right before she hits the water is equal to 2450 J.

You might be interested in

How do you find distance from average velocity and time

AlekseyPX

Answer:

Calculate the total distance travelled by the object - its motion is represented by the velocity-time graph below.

Here, the distance travelled can be found by calculating the total area of the shaded sections below the line.

½ × base × height.

½ × 4 × 8 = 16 m 2

(10 – 4) × 8 = 48 m 2

Explanation:

7 0

3 years ago

The lightning bolt discharge lasts one millisecond. What is the average current flowing from the cloud to ground? Answer in unit

denpristay [2]

Answer:

25100A

Explanation:

t= 1ms = 0.001s

q = 25.1C

From the relationship between charge and current , the charge is equal to the product of current and time

q = i×t

Where q = charge

i = current

t = time

i = q/t = 25.1/0.001

i = 25100A.

5 0

3 years ago

A night-light uses 3 W.If the voltage is 120 V, what is the current? A.0.025A B.40 A C.360A D.0.25A

Tomtit [17]

The answer to this question is A.

6 0

3 years ago

A 0.150 kg mass is attached to a spring with k = 18.9 N/m. At the equilibrium position, it moves 2.39 m/s. How much mechanical e

Nastasia [14]

Answer:0.428

Explanation: got it right on Acellus

5 0

3 years ago

Tennis balls traveling at greater than 100 mph routinely bounce off tennis rackets. At some sufficiently high speed, however, th

Kipish [7]

Answer:

Probability of tunneling is $10^{- 1.17\times 10^{32}}$

Solution:

As per the question:

Velocity of the tennis ball, v = 120 mph = 54 m/s

Mass of the tennis ball, m = 100 g = 0.1 kg

Thickness of the tennis ball, t = 2.0 mm = $2.0\times 10^{- 3}\ m$

Max velocity of the tennis ball, $v_{m} = 200\ mph$ = 89 m/s

Now,

The maximum kinetic energy of the tennis ball is given by:

$KE = \frac{1}{2}mv_{m}^{2} = \frac{1}{2}\times 0.1\times 89^{2} = 396.05\ J$

Kinetic energy of the tennis ball, KE' = $\frac{1}{2}mv^{2} = 0.5\times 0.1\times 54^{2} = 154.8\ m/s$

Now, the distance the ball can penetrate to is given by:

$\eta = \frac{\bar{h}}{\sqrt{2m(KE - KE')}}$

$\bar{h} = \frac{h}{2\pi} = \frac{6.626\times 10^{- 34}}{2\pi} = 1.0545\times 10^{- 34}\ Js$

Thus

$\eta = \frac{1.0545\times 10^{- 34}}{\sqrt{2\times 0.1(396.05 - 154.8)}}$

$\eta = 1.52\times 10^{-35}\ m$

Now,

We can calculate the tunneling probability as:

$P(t) = e^{\frac{- 2t}{\eta}}$

$P(t) = e^{\frac{- 2\times 2.0\times 10^{- 3}}{1.52\times 10^{-35}}} = e^{-2.63\times 10^{32}}$

$P(t) = e^{-2.63\times 10^{32}}$

Taking log on both the sides:

$logP(t) = -2.63\times 10^{32} loge$

$P(t) = 10^{- 1.17\times 10^{32}}$

6 0

3 years ago