2. After you cross the finish line, you slow

natali 33 [55]

By putting to much weight on it our body causing it to hurt or fall hope this helps

8 0

3 years ago

A force of 10 lb is required to hold a spring stretched 4 in. beyond its natural length. How much work W is done in stretching i

Sunny_sXe [5.5K]

Answer:

114.44 J

Explanation:

From Hook's Law,

F = ke................. Equation 1

Where F = Force required to stretch the spring, k = spring constant, e = extension.

make k the subject of the equation

k = F/e.............. Equation 2

Given: F = 10 lb = (10×4.45) N = 44.5 N, e = 4 in = (4×0.254) = 1.016 m.

Substitute into equation 2

k = 44.5/1.016

k = 43.799 N/m

Work done in stretching the 9 in beyond its natural length

W = 1/2ke²................. Equation 3

Given: e = 9 in = (9×0.254) = 2.286 m, k = 43.799 N/m

Substitute into equation 3

W = 1/2×43.799×2.286²

W = 114.44 J

3 0

4 years ago

Read 2 more answers

Which situations might cause two observers (A and B) to measure different frequencies for the same vibrating object? Select the

Alex787 [66]

We want to explain why two different observes may measure different frequencies for the same vibrating object.

We will see that the two correct options are:

Observer A is stationary and Observer B is moving.
Observer A and Observer B are moving at different speeds relative to each other.

Let's assume that the vibrating object is a guitar string. Thus, the string makes a noise, and from that noise, we can estimate the frequency at which the string vibrates.

Now there appears a really cool effect, called the Doppler Effect. It says that the apparent change of frequency is due to the motion of the observer or the source of the frequency (or both).

For example, if you move towards the vibrating string, the perceived frequency will be larger, and you will hear a "higher" sound.

While if you move away from the string, the opposite happens, and you will hear a "lower" sound.

Then the only thing that impacts in how we perceive the frequency is our velocity relative to the source.

So, why do observers A and B measure different frequencies?

The two correct answers are:

Observer A is stationary and Observer B is moving.
Observer A and Observer B are moving at different speeds relative to each other.

If you want to learn more, you can read:

brainly.com/question/17107808

6 0

3 years ago

Which of the following is not an example of a chemical reaction? Rust, Photosynthesis, Melting Ice, Heat from Fire?

FinnZ [79.3K]

Rust, photosynthesis, and heat from fire are all chemical reactions because new substances are formed and the chemical formula is changed. By doing this, bonds are broken and formed in the making of the new substance. Melting ice is physical change the molecules are still water molecules, it just changed physical form.

5 0

3 years ago

Read 2 more answers

A rocket starting from its launch pad is subjected to a uniform acceleration of 100 meters/second2. Determine the time needed to

balandron [24]

The velocity is the integral of acceleration. If acceleration is 100 m/s^2 then velocity is:

$v= \int\limits^{}_{}100 \, dt=100t$

So to know the velocity at any time, t, we just put t in seconds into this equation. To know at what time we get to a certain velocity, we set this equation equal to that velocity and solve for t:

$100t = 1000 \\ \\ t= \frac{1000}{100} =10s$

5 0

3 years ago