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3 years ago

What 2 things need to be known about an object in order to determine its kinetic energy?

Physics

1 answer:

NikAS [45]3 years ago

7 0

I believe the answer is the mass of the object and the speed at which it is moving.

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How far did the object travel by the end of eight seconds, according to the graph above?

Ulleksa [173]

Answer:

<em>The object traveled 4 cm by the end of eight seconds.</em> Correct: A)

Explanation:

<u>Speed vs Time Graph</u>

In a speed-time graph, speed is plotted on the vertical axis and time is plotted on the horizontal axis. If the graph is a horizontal line, the speed is constant, if the line is sloped up, the speed is increasing and the acceleration is positive and constant, and if the line is sloped down, the speed is decreasing and the acceleration is negative and constant.

The distance traveled by the object can be found by calculating the area under the graph and above the x-axis.

The graph provided shows two different zones: the first 4 seconds, the speed is constant at 1 cm/s, and the last 4 seconds, the speed is zero, i.e. the object is not moving.

The area behind the first zone is a rectangle of height 1 cm/s and base 4 sec, thus the distance is 1 * 4 = 4 centimeters.

The second zone corresponds to an object at rest, thus no distance is traveled.

The object traveled 4 cm by the end of eight seconds.

A) Correct. As shown above

B) The distance traveled is 4 cm. Incorrect

C) The distance traveled is 4 cm. Incorrect

D) The distance traveled is 4 cm. Incorrect

6 0

3 years ago

If an object is not moving, what do we know about the forces acting on it?

Nat2105 [25]

I think it should be 'They are balanced' if I'm not wrong

7 0

3 years ago

Read 2 more answers

Two astronauts on opposite ends of a spaceship are comparing lunches. One has an apple, the other has an orange. They decide to

lbvjy [14]

Answer:

Explanation:

We shall consider direction towards left as positive Let the required velocity be v and let v makes an angle φ

Applying law of conservation of momentum along direction of original motion

m₁ v₁ - m₂ v₂ = m₂v₃ - m₁ v₄

0.132 x 1.25 - .143 x 1.14 = 1.03 cos43 x .143 - v cos θ

v cos θ = .8

Applying law of conservation of momentum along direction perpendicular to direction of original motion

1.03 sin 43 x .143 = .132 x v sinθ

v sinθ = .76

squaring and adding

v² = .76 ² + .8²

v = 1.1 m /s

Tan θ = .76 / .8

θ = 44°

6 0

3 years ago

Arigid body must rotate about an axis in order for it to have angular momentum about that axis. True False

kompoz [17]

Answer:

False

Explanation:

Let's consider the definition of the angular momentum,

$\vec{L} = I \vec{\omega}$

where $I = \int\limits_m r^2 dm = \lim_{n \to \infty} \sum\limits_{i=1}^n m_i r_i^2$ is the moment of inertia for a rigid body. Now, this moment of inertia could change if we change the axis of rotation, because "r" is defined as the distance between the puntual mass and the nearest point on the axis of rotation, but still it's going to have some value. On the other hand,

$\vec{\omega} = \frac{\vec{r} \times \vec{v}}{r^2}$ so $\vec{\omega} \neq 0$ unless $\vec{r}$ ║ $\vec{v}$ .

In conclusion, a rigid body could rotate about certain axis, generating an angular momentum, but if you choose another axis, there could be some parts of the rigid body rotating around the new axis, especially if there is a projection of the old axis in the new one.

7 0

3 years ago

If light moves at a speed of 299,792,458 m/s, how long will it take light to move a distance of 1,000 km

astra-53 [7]

Answer:

change 1000km into Metre

1000km=1000000 M

speed= distance/time

time=distance/speed

time=1000000/299792458

time= 0.0033second

6 0

2 years ago