An object in projectile motion will follow which path?

Which of the following are inertial reference frames? A. A car driving at steady speed on a straight and level road. B. A car dr

Aloiza [94]

Answers:

A. A car driving at steady speed on a straight and level road.

B. A car driving at steady speed up a 10∘ incline.

Explanation:

An object is said to be in an inertial reference frame if the net force acting on the object is zero. According to Newton's second law, this also means that the acceleration of the object is also zero:

$F=ma$

Since F=0, a=0 as well.

Let's now analyze each case.

A. A car driving at steady speed on a straight and level road. --> YES: this is an inertial reference frame, because the car is keeping a constant speed and a constant direction, so its velocity is not changing, and its acceleration is zero.

B. A car driving at steady speed up a 10∘ incline. --> YES: this is an inertial reference frame, because the car is keeping a constant speed and a constant direction, so its velocity is not changing, and its acceleration is zero.

C. A car speeding up after leaving a stop sign. --> NO: this is not an intertial reference frame, because the car is speeding up, so it is accelerating.

D. A car driving at steady speed around a curve. --> NO: this is not an inertial reference frame, because the car is changing direction, therefore its velocity is changing and so the car is accelerating.

So the only two choices which are correct are A and B.

8 0

3 years ago

Read 2 more answers

Anyone good with scientific notations? I sure am not

defon

B is the answer that I know of.

7 0

3 years ago

Read 2 more answers

A thin uniform rod of mass M and length L is bent at its center so that the two segments are now perpendicular to each other. Fi

Tatiana [17]

Answer:

(a) I_A=1/12ML²

(b) I_B=1/3ML²

Explanation:

We know that the moment of inertia of a rod of mass M and lenght L about its center is 1/12ML².

(a) If the rod is bent exactly at its center, the distance from every point of the rod to the axis doesn't change. Since the moment of inertia depends on the distance of every mass to this axis, the moment of inertia remains the same. In other words, I_A=1/12ML².

(b) The two ends and the point where the two segments meet form an isorrectangle triangle. So the distance between the ends d can be calculated using the Pythagorean Theorem:

$d=\sqrt{(\frac{1}{2}L) ^{2}+(\frac{1}{2}L) ^{2} } =\sqrt{\frac{1}{2}L^{2} } =\frac{1}{\sqrt{2} } L=\frac{\sqrt{2} }{2} L$

Next, the point where the two segments meet, the midpoint of the line connecting the two ends of the rod, and an end of the rod form another rectangle triangle, so we can calculate the distance between the two axis x using Pythagorean Theorem again:

$x=\sqrt{(\frac{1}{2}L)^{2}-(\frac{\sqrt{2}}{4}L) ^{2} } =\sqrt{\frac{1}{8} L^{2} } =\frac{1}{2\sqrt{2}} L=\frac{\sqrt{2}}{4} L$

Finally, using the Parallel Axis Theorem, we calculate I_B:

$I_B=I_A+Mx^{2} \\\\I_B=\frac{1}{12} ML^{2} +\frac{1}{4} ML^{2} =\frac{1}{3} ML^{2}$

5 0

3 years ago

3. A horizontally moving tennis ball barely clears the net, a distance y above the surface of the court. To land within the tenn

maksim [4K]

(a) The ball’s maximum speed over the net is v(max) = √2gh.

(b) The maximum speed of the horizontally moving ball clearing the net is about 27 m/s.

(c) Speed of the ball is independent of its mass.

<h3>Time of motion of the ball</h3>

The time of motion of the ball is calculated as follows;

h = vt + ¹/₂gt²

1 = 0 + ¹/₂(9.8)t²

1 = 4.9t²

t² = 1/4.9

t² = 0.204

t = 0.452 s

<h3>Horizontal speed of the ball</h3>

The horizontal speed of the ball is calculated as follows;

X = vt

v = X/t

v = (12 m)/(0.452)

v = 26.6 m/s ≈ 27 m/s (proved)

<h3>Conservation of energy</h3>

P.E = K.E

mgh = ¹/₂mv²

gh = ¹/₂v²

2gh = v²

√2gh = v(max)

Speed of the ball is independent of its mass.

Learn more about horizontal velocity here: brainly.com/question/24681896

#SPJ1

6 0

2 years ago

Which of the following are evidence for the big bang theory

irina1246 [14]

Answer:

Big Bang theory has occurred because about two thousand million years ago, a star came close to the sun. The molten mass on it melted and formed a huge mountain. Due to the high pressure, the star repelled back and the mountain separated into pieces. These pieces started revolving aound the sun and are known as planets. The existence of these planets is known as big bang theory.

Explanation:

4 0

3 years ago