When the moon passes between the sun and Earth ,the side that faces the Earth is in darkness

A rock is thrown vertically upward from some height above the ground. It rises to some maximum height and falls back to the grou

True [87]

Answer:

At the highest point the velocity is zero, the acceleration is directed downward.

Explanation:

This is a free-fall problem, in the case of something being thrown or dropped, the acceleration is equal to -gravity, so -9.80m/s^2. So, the acceleration is never 0 here.

I attached an image from my lecture today, I find it to be helpful. You can see that because of gravity the acceleration is pulled downwards.

At the highest point the velocity is 0, but it's changing direction and that's why there's still an acceleration there.

6 0

3 years ago

14

Minchanka [31]

Answer:

C

Explanation:

8 0

2 years ago

Read 2 more answers

I need help on 18,19,20 and 21

Dmitriy789 [7]

When a relationship between two different things is shown in a fraction it is a ratio.

hope this helps :)

8 0

2 years ago

Which of the following is an example of a force<br> inertia<br> push <br> pull

Whitepunk [10]

A force can be considered a push or pull

hope this helps :)

8 0

2 years ago

Four forces are exerted on a disk of radius R that is free to spin about its center, as shown above. The magnitudes are proporti

Dmitry_Shevchenko [17]

The given magnitude of forces of F₁ = F₄, F₂ = F₃, F₁ = 2·F₂, give the

forces that exert zero net torque on the disk as the options;

(B) F₂

(D) F₄

<h3>How can the net torque on the disk be calculated?</h3>

The given parameters are;

F₁ = F₄

F₂ = F₃

F₁ = 2·F₂

Therefore;

F₄ = 2·F₂

In vector form, we have;

$\vec{F_4} = \mathbf{\frac{\sqrt{3} }{2} \cdot F_4 \cdot \hat i - 0.5 \cdot F_4 \hat j}$

$\vec{F_2} = \mathbf{ -F_2 \, \hat j}$

Clockwise moment due to F₄, M₁ = $-0.5 \times F_4 \, \hat j \times \dfrac{R}{2}$

Therefore;

$M_1 =- 0.5 \times 2 \times F_2 \, \hat j \times \dfrac{R}{2} = \mathbf{ -F_2 \, \hat j \times \dfrac{R}{2}}$

Counterclockwise moment due to F₂ = $-F_2 \, \hat j \times \dfrac{R}{2}$

Given that the clockwise moment due to F₄ = The counterclockwise moment due to F₂, we have;

Two forces that combine to exert zero net torque on the disk are;

F₂, and F₄

Which are the options; (B) F₂, and (D) F₄

Learn more about the resolution of vectors here:

brainly.com/question/1858958

4 0

1 year ago