How much physical activity should an adult have each week?

A mass m is attached to a spring which is held stretched a distance x by a force f (fig. 7-28), and then released. the spring co

guapka [62]

Spring is stretched by force f to distance "x"

now here by force balance we can say

$f = kx$

$k = \frac{f}{x}$

now here we will we say that energy stored in the spring will convert into kinetic energy

$\frac{1}{2} kx^2 = \frac{1}{2}mv^2$

$\frac{f}{x} (x^2} = mv^2$

now solving above equation we will have

$v =\sqrt{ \frac{fx}{m}}$

PART 2)

now for half of the extension again we can use energy conservation

$\frac{1}{2}kx^2 - \frac{1}{2}k(x/2)^2 = \frac{1}{2} mv^2$

$\frac{3}{4}kx^2 = mv^2$

$\frac{3}{4}fx = mv^2$

now the speed is given as

$v = \sqrt{\frac{3fx}{4m}}$

5 0

3 years ago

Read 2 more answers

When Bob needs to send Alice a message with a digital signature, whose private key is used to encrypt the hash?

nadya68 [22]

Answer: Bob's private key

Explanation:

Since Bob is sending Alice the message, it simply implies he must have encrypted it with his key that Alice can be able to use to decrypt the message.

3 0

3 years ago

Distinguish between force and friction. class 8

KengaRu [80]

Answer: Friction is the resistance to motion of one object moving relative to another. For example, when you try to push a book along the floor, friction makes this difficult. Force: Force is essentially a push, or a pull action, that can lead to certain outcomes.

7 0

2 years ago

Cassie is an engineering undergrad. She does not like talking much, and has become a quiet and withdrawn person while in her pro

stepan [7]

Answer:

A

Explanation:

Analytical people are less responsive to others. They hence tend to focus more on work than people and are less interested in leading, being happier to work by themselves. They may be prudent and systematic, making them good at analytic work.

Some character traits of Analytical people

Focuses on work and working more than people

Likes to be correct and will take time to ensure this

Thoughtful, careful fact-oriented and precise

Good at problem-solving

Likes organization and structure

Avoids working in a group, preferring to work alone

Can be over-critical and unresponsive

Cautious in decision-making

When stressed may withdraw or become headstrong

8 0

3 years ago

A 200g piece of iron is heated at 100C. It is than dropped into water to bring its temperature down to 22C. What is the amount o

gizmo_the_mogwai [7]

Answer:

6926.4J

Explanation:

Given parameters:

Mass of iron = 200g

Initial temperature = 100°C

Final temperature = 22°C

Unknown:

Amount of heat transferred to the water = ?

Solution:

The quantity of heat transferred to the water is a function of mass and temperature of the iron;

H = m c Ф

m is the mass of the iron

Ф is the change in temperature

C is the specific heat capacity of iron = 0.444 J/g°C

Now;

insert the parameters and solve;

H = 200 x 0.444 x (100-22)

H = 6926.4J

8 0

3 years ago