What organ system sends signals from the brain to the muscles?

A 6.99-g bullet is moving horizontally with a velocity of +341 m/s, where the sign + indicates that it is moving to the right (s

Ratling [72]

Answer:

a). 1.218 m/s

b). R=2.8 $^{-3}$

Explanation:

$m_{bullet}=6.99g*\frac{1kg}{1000g}=6.99x10^{-3}kg$

$v_{bullet}=341\frac{m}{s}$

Momentum of the motion the first part of the motion have a momentum that is:

$P_{1}=m_{bullet}*v_{bullet}$

$P_{1}=6.99x10^{-3}kg*341\frac{m}{s} \\P_{1}=2.3529$

The final momentum is the motion before the action so:

a).

$P_{2}=m_{b1}*v_{fbullet}+(m_{b2}+m_{bullet})*v_{f}}$

$P_{2}=1.202 kg*0.554\frac{m}{s}+(1.523kg+6.99x10^{-3}kg)*v_{f}$

$P_{1}=P_{2}$

$2.529=0.665+(1.5299)*v_{f}\\v_{f}=\frac{1.864}{1.5299}\\v_{f}=1.218 \frac{m}{s}$

b).

kinetic energy

$K=\frac{1}{2}*m*(v)^{2}$

Kinetic energy after

$Ka=\frac{1}{2}*1.202*(0.554)^{2}+\frac{1}{2}*1.523*(1.218)^{2}\\Ka=1.142 J$

Kinetic energy before

$Kb=\frac{1}{2}*mb*(vf)^{2}\\Kb=\frac{1}{2}*6.99x10^{-3}kg*(341)^{2}\\Kb=406.4J$

Ratio = $\frac{Ka}{Kb}$

$R=\frac{1.14}{406.4}\\R=2.8x10^{-3}$

3 0

4 years ago

uppose that white light strikes a flat piece of flint glass in air, coming in at an angle of 60 degrees to the surface (30 degre

Elodia [21]

Answer:

Explanation:

Snell's law for index of refraction of a medium is as follows .

sin i / sin r = μ

i is angle of incidence , r is angle of refraction and μ is refractive index.

sin r = sin i / μ .

As μ for blue light is greatest , angle of refraction for blue light will be least . Similarly , angle of refraction will be maximum for red light .

So maximum deviation in the direction of light will occur in blue light due to least angle of refraction because

deviation angle = angle of incidence - angle of refraction .

So the order of light from inward towards surface

= blue , green , red .

7 0

3 years ago

Which statement is true according to Hooke's law?

Mkey [24]

Hooke's law:

F = -kx

F is the spring force, k is the spring constant, and x is the displacement of the spring. The negative sign is there to indicate that the force acts in the opposite direction of the displacement (e.g. if you stretch a spring towards the right, you will feel a force pulling towards the left).

Looking at Hooke's law, the magnitude of the force is directly proportional to its displacement; that is to say, if the displacement increases, so does the magnitude of the spring force, and if the magnitude of the force increases, this necessitates an increase in the displacement.

1. As the force on a spring increases, the distance it stretches decreases.

An increase in force necessitates an increase in displacement. This statement is false.

2. As the force on a spring increases, the distance it stretches increases.

An increase in force necessitates an increase in displacement. This statement is true.

3. As the force on a spring increases, the spring's length remains unchanged.

An increase in force necessitates an increase in displacement. This statement is false.

4. The distance a spring stretches has nothing to do with how much force is applied to it.

Hooke's law shows that the spring force and its displacement are very much dependent on each other. This statement is false.

Only statement 2 is true. As the force on a spring increases, the distance it stretches increases.

3 0

3 years ago

Objects with less density than water will?

ruslelena [56]

Objects with less density than water will float when you put them in water.

Objects with greater density than water will sink when you put them in water.

6 0

3 years ago

A teacher pushed a 98 newton desk across a floor for a distance of 5 meter he exerted a horizontal force of 20 newton for four s

Rom4ik [11]

Missing question: "how much work is done by the teacher?" (found on internet)

Solution:
The work done to move the desk across the floor is equal to
$W=Fd$
where F is the horizontal force applied to move the desk, and d is the distance covered by the desk. If we use F=20 N and d=5 m, we find the work done:
$W=Fd=(20 N)(5 m)=100 J$

3 0

3 years ago