Which group contains elements that have the following characteristics:
1 answer:
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Answer:
-9.46 N
Explanation:
In order to get the value of the x component of the resultant force, we need to get the value of the x component of each force.
This value will be the projection of the force vector, on the x-axis.
For F₁, as it is directed at an angle of 55.0º above the negative x axis, we can find F₁ₓ just applying the definition of cosine of an angle, as follows:
cos θ =
In this case, x = F₁ₓ, and r = F₁
θ, measured from the positive x axis counterclockwise, is as follows:
θ= 180º-55º = 125º
⇒ F₁ₓ = F₁* cosθ = 9.2 N * cos 125º = -5.28 N
We can repeat the process for F₂, as follows:
For F₂, as it is directed at an angle of 53.3º below the negative x axis, we can find F₂ₓ just applying the definition of cosine of an angle, as follows:
cos θ =
In this case, x = F₂ₓ, and r = F₂
θ, measured from the positive x axis counterclockwise, is as follows:
θ= 180º + 53.3º = 233.3º
⇒ F₂ₓ = F₂* cosθ = 7.00 N * cos 233.3º = -4.18 N
The total component of both forces along the x axis, can be found just adding both components, as follows:
Fₓ = F₁ₓ + F₂ₓ = -5.28 N + -4.18 N = -9.46 N
Answer:
0.799 m/s if air resistance is negligible.
Explanation:
For how long is the ball in the air?
Acceleration is constant. The change in the ball's height depends on the square of the time:
,
where
is the change in the ball's height.
is the acceleration due to gravity.
is the time for which the ball is in the air.
is the initial vertical velocity of the ball.
- The height of the ball decreases, so this value should be the opposite of the height of the table relative to the ground.
.
- Gravity pulls objects toward the earth, so
near the surface of the earth.
- Assume that the table is flat. The vertical velocity of the ball will be zero until it falls off the edge. As a result,
.
Solve for .
;
;
;
.
What's the initial horizontal velocity of the ball?
- Horizontal displacement of the ball:
;
- Time taken:
Assume that air resistance is negligible. Only gravity is acting on the ball when it falls from the tabletop. The horizontal velocity of the ball will not change while the ball is in the air. In other words, the ball will move away from the table at the same speed at which it rolls towards the edge.
.
Both values from the question come with 3 significant figures. Keep more significant figures than that during the calculation and round the final result to the same number of significant figures.