If you have 5.112 grams of ammonia (NH3), then how many molecules of ammonia do you have?

Kinetic friction is affected by the weight of the object. True or false?

nevsk [136]

True Kinetic friction is affected by the weight of the object

3 0

3 years ago

A 0.40 kg ball is suspended from a spring with spring constant 12 n/m . part a if the ball is pulled down 0.20 m from the equili

PolarNik [594]

The total mechanical energy of the system at any time t is the sum of the kinetic energy of motion of the ball and the elastic potential energy stored in the spring:
$E=K+U= \frac{1}{2}mv^2+ \frac{1}{2}kx^2$
where m is the mass of the ball, v its speed, k the spring constant and x the displacement of the spring with respect its rest position.

Since it is a harmonic motion, kinetic energy is continuously converted into elastic potential energy and vice-versa.

When the spring is at its maximum displacement, the elastic potential energy is maximum (because the displacement x is maximum) while the kinetic energy is zero (because the velocity of the ball is zero), so in this situation we have:
$E=U_{max}= \frac{1}{2}k(x_{max})^2$

Instead, when the spring crosses its rest position, the elastic potential energy is zero (because x=0) and therefore the kinetic energy is at maximum (and so, the ball is at its maximum speed):
$E=K_{max}= \frac{1}{2}m(v_{max})^2$

Since the total energy E is always conserved, the maximum elastic potential energy should be equal to the maximum kinetic energy, and so we can find the value of the maximum speed of the ball:
$U_{max}=K_{max}$
$\frac{1}{2}k(x_{max})^2 = \frac{1}{2}m(v_{max})^2$
$v_{max}= \sqrt{ \frac{k x_{max}^2}{m} }= \sqrt{ \frac{(12 N/m)(0.20 m)^2}{0.4 kg} }=1.1 m/s$

3 0

3 years ago

The _____ of an object consists of its speed and direction.

ELEN [110]

Velocity would be an answer

3 0

2 years ago

A current of 0.001 A can be felt by the human body. 0.005 A can produce a pain response. 0.015 A can cause a loss of muscle cont

lys-0071 [83]

Answer:

In summary, it is safe to handle this voltage with dry hands because the current value that you pass through the body is smaller than its underestimated sensitivity.

Explanation:

The current flowing through your system is described by Ohm's law

V = I R

where I is the current, V the voltage and R the resistance

in this case three barateras are taken in series giving a total voltage of V = 4.5 V the typical resistance values of dry skin is R = 1000 000Ohm and the resinification of wet skin is R = 100000 ohm

let's calculate the current flowing

I = V / R

I = 4.5 / 1000000

I = 4.5 10⁻⁶ A

this is the current with dry hands, we see that much less than the value that allows to feel a painful response by the body

If the skin is

I = 4,5 / 100,000

I = 4.5 10⁻⁵ A

This value is small, but it is close to the pain threshold, but it is in the range of slight discomfort.

In summary, it is safe to handle this voltage with dry hands because the current value that you pass through the body is smaller than its underestimated sensitivity.

7 0

3 years ago

A track coach records how long it takes a sprinter to run 100 meters the track coach is recording what dimension of behavior

melamori03 [73]

Behavior has at least six dimensions, which are: frequency, duration, latency, topography, locus, and force. Since the coach is recording how long it takes, the track coach is recording the duration behavior because duration is a synonym for time. Duration is your answer.

5 0

3 years ago