The position-time graph describes the motion of a moving object. Describe the motion represented by each segment of the graph.

Which of the following represents a joule?

Andru [333]

Answer:

d. N*m

Explanation:

Workdone which is measured in Joules is calculated using the formula;

Workdone = force * distance

Where;

Force is measured in Newton

Distance is measured in meters.

Therefore, workdone also has the measurement of Newton-meters.

5 0

3 years ago

A father racing his son has half the kinetic energy of the son, who has half the mass of the father.The father speeds up by 1.0

Helga [31]

Answer:

(a) $v_f=2.414\ m.s^{-1}$

(b) $v_s=4.828\ m.s^{-1}$

Explanation:

Let:

mass of father be, $m_f$

mass of son be, $m_s=\frac{m_f}{2}$

speed of son be, $v_s$

initial speed of father be, $v_f$

After speeding up, speed of father is $v_f+1$

We know Kinetic Energy is given as

$KE=\frac{1}{2} m.v^2$ .....................................(1)

where:

m = mass

v = velocity

Hence, according to the initial condition the father is having kinetic energy half the kinetic energy of the son.

$KE_s=2.KE_f$

$\frac{1}{2} m_s.v_s^2=2\times \frac{1}{2} m_f.v_f^2$

$(\frac{m_f}{2})\times v_s^2=2\times m_f\times v_f^2$

$v_s=2v_f$ .................................................(2)

According to the final condition:

$\frac{1}{2} m_s.v_s^2= \frac{1}{2} m_f.(v_f+1)^2$

$(\frac{m_f}{2})\times v_s^2=m_f.(v_f+1)^2$

$v_s^2=2(v_f+1)^2$

$v_s=\sqrt{2}(v_f+1)$ .....................................................(3)

(a)

From eq. 2 & 3

$2v_f=\sqrt{2}(v_f+1)$

$\sqrt{2}\ v_f=(v_f+1)$

$v_f(\sqrt{2}-1)=1$

$v_f=\frac{1}{(\sqrt{2}-1)}$

$v_f=2.414\ m.s^{-1}$

(b)

putting the above value in eq. (2)

$v_s=4.828\ m.s^{-1}$

4 0

4 years ago

The graph is tied to the reading

AleksandrR [38]

I. Positive acceleration increases velocity. Negative acceleration decreases velocity. runner A sped up until the finish line and then slowed to a stop.

ii. Zero a acceleration implies a constant, unchanging velocity not a zero velocity. runner B achieved some velocity prior to 8s and is moving and must slow down to reach a stop.

iii. None. No aspects of this reasoning are correct. Everything she says is wrong. See iv for what/why.

iv. The sign on acceleration denotes the direction of *change in velocity* not change in direction. The sign on velocity can denote change in direction but only “forward” or “reverse” along a particular path. Cardinal direction is not indicated, generally, by the sign on velocity. It may correspond to North/South situationally but it is not an built-in feature of velocity and its sign. For example, if you are traveling with positive velocity and turn left to continue your journey you still have a positive velocity in the new direction. In fact, if you turn left again, traveling in the opposite direction as the one you started with your velocity would still be positive… in the new direction. The velocity relative to original direction could be said to be negative but that would be a confusing way to describe a journey. Maybe if you stopped the vehicle and moved in reverse, you could meaningfully say velocity was negative.

5 0

3 years ago

2) A molecule of hydrochloric acid HCl contains one atom of hydrogen and *

Dimas [21]

Answer:

3

Explanation:

because I put that it's was right

3 0

3 years ago

Your question: "the picture shows a professional diver with a mass of 93 kg from a 25 m high cliff. Earths Gravity is acting on

GuDViN [60]

When we see the words "Which statement ... ", we know right away that there
will be a list of choices, and we're expected to select our answer from that list.
Strangely, the list of answer-choices for this question has been lost.

Similarly, when we see the words "The picture shows ... ", it's hard to fight
the impulse to look around. In the present situation, that's missing too.

If the diver is just standing there, then the reaction force provided by the cliff
against his feet must be exactly equal to his weight. If the vertical forces acting
on the soles of his feet were not balanced, then his feet would be accelerating
vertically.

His weight is (mass) x (gravity) =

(93 kg) x (9.8 m/s²) = 911.4 newtons (about 205 pounds) .

That's also the strength of the upward reaction force provided by the cliff.

6 0

4 years ago