All categories

2 years ago

Please help me I will give a brainless

Physics

1 answer:

gulaghasi [49]2 years ago

4 0

Answer:

By opening the door, Elijah is using the chemical energy, which he obtained from eating food to do work. Thus, he is converting chemical energy to mechanical energy.

Stretching the spring by opening the screen door convert the potential energy which is stored in the spring to kinetic energy.

Overall there is conversion of chemical energy to potential energy.

By letting the door go, Elijah is using chemical energy. By snapping shut, the door is converting potential energy to kinetic energy. The overall energy change is conversion of chemical energy to kinetic energy.

Explanation:

You might be interested in

What is the Mirror equation? What does it look like?

kipiarov [429]

Answer:

1/f = 1/D' + 1/D

The magnification equation relates the ratio of the image distance and object distance to the ratio of the image height (h^i) and object height (h^o). The magnification equation is stated as follows:

M= H^i/H^o = D^i/D^o

7 0

2 years ago

A 41 kg girl and a 5.0 kg sled are on the frictionless ice of a frozen lake, 15 m apart but connected by a rope of negligible ma

goldfiish [28.3K]

(a) 0.8 m/s^2

The force exerted on the sled is F = 4.0 N. We can calculate the acceleration of the sled by using Newton's second law:

$F=ma$

where

m = 5.0 kg is the mass of the sled

a is the acceleration of the sled

Solving the equation for a, we find:

$a=\frac{F}{m}=\frac{4.0 N}{5.0 kg}=0.8 m/s^2$

(b) 0.098 m/s^2

According to Newton's third law (action-reaction law), since the girl exerts a force on the sled, then the sled exerts an equal and opposite force on the girl as well. This means that the force exerted on the girl is also F = 4.0 N. As before, we can calculate the acceleration of the girl by using Newton's second law:

$F=ma$

where

m = 41 kg is the mass of the girl

a is the acceleration of the girl

Solving the equation for a, we find:

$a=\frac{F}{m}=\frac{4.0 N}{41 kg}=0.098 m/s^2$

(c) 5.8 s

Taking the initial position of the girl as x = 0, the position at time t of the girl is given by:

$x(t)=\frac{1}{2}a_g t^2$

where $a_g = 0.098 m/s^2$ is the acceleration of the girl.

The sled starts instead its motion from x = 15 m, so its position at time t is given by

$x'(t)=15-\frac{1}{2}a_s t^2$

where $a_s=0.8 m/s^2$ is the acceleration of the sled, and the negative sign is due to the fact that the sled accelerates in opposite direction to the girl's acceleration.

The girl and the sled meet when x(t) = x'(t). So, we find:

$\frac{1}{2}a_g t^2=15-\frac{1}{2}a_s t^2\\(a_g+a_s) t^2=30 m\\t=\sqrt{\frac{30 m}{a_g+a_s}}=\sqrt{\frac{30 m}{0.8 m/s^2+0.098 m/s^2}}=5.8 s$

4 0

3 years ago

A solenoidal coil with 25 turns of wire is wound tightly around another coil with 310 turns. the inner solenoid is 25.0 cm long

Ymorist [56]

(a) Image 1
(b) Image 2
(c) Image 3

6 0

3 years ago

Identify one force acting on the cart.

Artist 52 [7]

Answer:

pulling force

Explanation:

because the person is pulling that cart.

5 0

3 years ago

A particle is in a general circular motion (tangential speed is not constant). Which one of the following statements is always c

timurjin [86]

Answer:

2. The velocity of the particle is tangent to the circle

Explanation:

1. The velocity of the particle is constant.

Incorrect

Reason : Since the tangential speed is not constant, hence the velocity of the particle is not constant.

2. The velocity of the particle is tangent to the circle.

Correct

Reason : In circular motion, the direction of velocity is always given by the tangent to the circle.

3. The acceleration of the particle is constant.

Incorrect

Reason : The tangential speed of the particle is not constant which in turn keeps changing the centripetal acceleration of the particle. hence the acceleration of the particle is not constant.

4. The acceleration of the particle is toward the center of circle.

Incorrect.

7 0

3 years ago