The brakes on a 15,680 N car exert a stopping force of 640 N.

The tow spring on a car has a spring constant of 3,086 N / m and is initially stretched 18.00 cm by a 100.0 kg college student o

sdas [7]

Answer:

The velocity of the skateboard is 0.774 m/s.

Explanation:

Given that,

The spring constant of the spring, k = 3086 N/m

The spring is stretched 18 cm or 0.18 m

Mass of the student, m = 100 kg

Potential energy of the spring, $P_f=20\ J$

To find,

The velocity of the car.

Solution,

It is a case of conservation of energy. The total energy of the system remains conserved. So,

$P_i=K_f+P_f$

$\dfrac{1}{2}kx^2=\dfrac{1}{2}mv^2+20$

$\dfrac{1}{2}\times 3086\times (0.18)^2=\dfrac{1}{2}mv^2+20$

$50-20=\dfrac{1}{2}mv^2$

$30=\dfrac{1}{2}mv^2$

$v=\sqrt{\dfrac{60}{100}}$

v = 0.774 m/s

So, the velocity of the skateboard is 0.774 m/s.

7 0

3 years ago

For her birthday, amy received flowers that had a dull red appearance. compared with the entire range of visible light waves, th

Cerrena [4.2K]

The flowers reflect relatively low frequency and low amplitude light waves.
White light contains a spectrum of colors, and red light is at the beginning of this spectrum in terms of energy. This means that it has the lowest frequency, as the energy of a wave of light is directly proportional to its frequency.
The amplitude of a light wave gives a measure of how intense the light is. A dull light means that the amplitude of the wave is low.

4 0

3 years ago

Two people push on the same door from opposite sides as shown.

tangare [24]

The correct answer is
<span>c. one person exerts more force than the other so that the forces are unbalanced.

In fact, the door is initially at rest. In order to move the door, a net force different from zero should be applied, according to Newton's second law:
</span> $\sum F = ma$
<span>where the term on the left is the resultant of the forces acting on the door, m is the door mass and a its acceleration.

In order to move the door, the acceleration must be different from zero. But this means that the resultant of the forces acting on it must be different from zero: this is possible only if the forces applied by the two persons are unbalanced, i.e. one person exerts more force than the other.</span>

3 0

3 years ago

Read 2 more answers

An object traveling 200 feet per second slows to 50 feet per second in 5 seconds. Calculate the acceleration of the object. Use

shtirl [24]

Answer:

-30m/s

Explanation:

Given:

Initial velocity of object = 200 feet/second

Final velocity of object = 50 feet/second

Time of travel = 5 seconds