The current flowing through a circuit can be measured by ?

A 75 kg bungee jumper leaps from a bridge. When he is 30 meters above the water, and moving at a speed of 20 m/s, the bungee cor

jasenka [17]

Answer:

k = 52.2 N / m

Explanation:

For this exercise we are going to use the conservation of mechanical energy.

Starting point. When it is 30 m high

Em₀ = K + U = ½ m v² + m g h

Final point. Right when you hit the water

$Em_{f}$ = K_{e} = ½ k x²

in this case the distance the bungee is stretched is 30 m

x = h

as they indicate that there are no losses, energy is conserved

Em₀ = Em_{f}

½ m v² + m g h = ½ k h²

k = $\frac{m (v^{2} + 2 g h)}{h^{2} }$

let's calculate

k = $\frac{75 \ ( 20^{2} + 2 \ 9.8 \ 30)}{30^{2} }$

k = 52.2 N / m

3 0

3 years ago

1. Why is it easier to change the motion of a large toy car than a small toy car?

insens350 [35]

Because it is acted upon by balanced forces.

Toy cars use a variety of mechanisms to make them go, but they all store up potential energy. Although the elastic material inside is usually steel and not rubber, the principle is the same. By changing the shape of the material (usually a coil of metal) energy is stored and then released as motion.

7 0

3 years ago

What is the best definition for work?

olga55 [171]

Work is done when a force is in the same direction as the object moves.

Explanation:

The work done by a force in moving an object is given by the equation

$W=Fd cos \theta$

where

F is the magnitude of the force

d is the displacement of the object

$\theta$ is the angle between the directions of F and d

From the equation, we notice the following:

Work is done by a force when the force is in the same direction as the object moves. In fact, in this case, $\theta=0^{\circ}$ , and so $cos \theta = 1$ , which means that the work done simply becomes $W=Fd$
When the force is perpendicular to the motion of the object, $\theta=90^{\circ}$ and $cos \theta = 0$ , which means that no work done
Technically, work is also done when the force is not parallel to the motion of the object: in this case, the factor $cos \theta$ means that only the component of the force parallel to the direction of motion contributes to do work on the object.

Therefore, the correct answer is

Work is done when a force is in the same direction as the object moves.

Learn more about work:

brainly.com/question/6763771

brainly.com/question/6443626

#LearnwithBrainly

7 0

4 years ago

A person is listening with his ear against the rail for an oncoming train. When the train is 1.65 km away, how long will it take

Vitek1552 [10]

Answer:

Time = 0.317 seconds.

Explanation:

Given the following data;

Distance = 1.65km to meters = 1.65 * 1000 = 1650 meters

We know that the speed of sound in steel is equal to 5200m/s

To find the time to hear the sound of the whistle;

Time = distance/speed

Substituting into the equation, we have

Time = 1650/5200

Time = 0.317 seconds.

Therefore, it will take him 0.317 seconds to hear the sound of the whistle.

3 0

3 years ago

A screen is placed 1.60 m behind a single slit. The central maximum in the resulting diffraction pattern on the screen is 1.40 c

Lunna [17]

Answer:

distance between the two second-order minima is 2.8 cm

Explanation:

Given data

distance = 1.60 m

central maximum = 1.40 cm

first-order diffraction minima = 1.40 cm

to find out

distance between the two second-order minima

solution

we know that fringe width = first-order diffraction minima /2

fringe width = 1.40 /2 = 0.7 cm

and

we know fringe width of first order we calculate slit d

β1 = m1λD/d

d = m1λD/β1

and

fringe width of second order

β2 = m2λD/d

β2 = m2λD / ( m1λD/β1 )

β2 = ( m2 / m1 ) β1

we know the two first-order diffraction minima are separated by 1.40 cm

so

y = 2β2 = 2 ( m2 / m1 ) β1

put here value

y = 2 ( 2 / 1 ) 0.7

y = 2.8 cm

so distance between the two second-order minima is 2.8 cm

6 0

3 years ago