All categories

4 years ago

Which example describes constant acceleration due ONLY to a change in direction?

Physics

2 answers:

Yakvenalex [24]4 years ago

6 0

Answer:

c. traveling around a circular track

Explanation:

Acceleration is defined as the rate of change of velocity per unit time:

$a=\frac{\Delta v}{\Delta t}$

However, velocity is a vector quantity. This means that acceleration can be due to:

- A change in the speed of an object, or

- A change in the direction of the object

Let's analyze each choice:

a. increasing speed while traveling around a curve --> in this case, both speed and direction are changing (the direction is changing since the object is moving around a curve), so this is not the correct choice

b. an object at rest --> here neither the speed nor the direction are changing (in fact, the object is not accelerating), so this is not the correct choice

c. traveling around a circular track --> here the direction is changing (because the track is circular), while we don't know anything about the speed. If we assume the speed to be constant, then this is the correct choice

d. an object in free fall --> here the speed is changing, while the direction not, so this is not the correct choice

Brut [27]4 years ago

5 0

'Traveling around a circular track' can be a description of constant
acceleration due only to changes in direction. But if it is, then the
progress around the circular track must be at constant speed.

You might be interested in

A 1.50 3 103 - kg car starts from rest and accelerates uniformly to 18.0 m/s in 12.0 s. Assume that air resistance remains const

nexus9112 [7]

Answer:

Explanation:

let force exerted by engine be F.Net force =( F-400)N, applying newton law

F-400 = 1.5 x 10³x18 =27000 ,

F = 27400 N.

velocity after 12 s = 0 + 18 x 12 = 216 m/s

Average velocity = (0 + 216 )/2 = 108 m/s

Average power = force x average velocity = 27400 x 108 = 29.6 10⁵ W .⁶

b) At 12 s , velocity = 216 m/s

Instantaneous power = velocity x force = 216 x 27400 = 59.2 x 10⁶ W.

8 0

3 years ago

Read 2 more answers

In developed nations, the water delivered to homes by pipe is generally potable. Please select the best answer from the choices

stiv31 [10]

True is ur answer sorry if i am too late

6 0

3 years ago

Read 2 more answers

A stoplight with weight 100 N is suspended at the midpoint of a cable strung between two posts 200 m apart. The attach points fo

Tasya [4]

There are 3 forces acting on the stoplight:

• its weight W, with magnitude W = 100 N, pointing directly downward

• two tension forces T₁ and T₂ with equal magnitude T₁ = T₂ = T = 1000 N, both making an angle of θ with the horizontal, but one points left and the other points right

The stoplight is in equilibrium, so by Newton's second law, the net vertical force acting on it is 0, such that

∑ F = T₁ sin(θ) + T₂ sin(180° - θ) - W = 0

We have sin(180° - θ) = sin(θ) for all θ, so the above reduces to

2T sin(θ) = W

2 (1000 N) sin(θ) = 100 N

sin(θ) = 0.05

θ ≈ 2.87°

If y is the vertical distance between the stoplight and the ground, then

tan(θ) = (15 m - y) / (100 m)

Solve for y :

tan(2.87°) = (15 m - y) / (100 m)

y = 15 m - (100 m) tan(2.87°)

y ≈ 9.99 m

3 0

3 years ago

Heather and Jerry are standing on a bridge 49 mm above a river. Heather throws a rock straight down with a speed of 17 m/sm/s .

lara [203]

Answer:

3.467 s

Explanation:

given,

distance , d = 49 mm = 0.049 m

initial speed of the of the rock, v = 17 m/s

time taken by the Heather rock to reach water

using equation of motion

$s = ut +\dfrac{1}{2}at^2$

taking downward as negative

$-0.049 = -17 t -\dfrac{1}{2}\times 9.8\times t^2$

4.9 t² + 17 t - 0.049 = 0

now,

$t_1 = \dfrac{-(17)\pm \sqrt{17^2 - 4\times 4.9 \times (-0.049)}}{2\times 4.9}$

t₁ = -3.47 s , 0.0028 s

rejecting negative values

t₁ = 0.0028 s

now, time taken by the ball of Jerry

using equation of motion

$s = ut +\dfrac{1}{2}at^2$

taking downward as negative

$-0.049 = 17 t -\dfrac{1}{2}\times 9.8\times t^2$

4.9 t² - 17 t - 0.049 = 0

now,

$t_2 = \dfrac{-(-17)\pm \sqrt{17^2 - 4\times 4.9 \times (-0.049)}}{2\times 4.9}$

t₂ = 3.47 s ,-0.0028 s

rejecting negative values

t₂ = 3.47 s

now, time elapsed is = t₂ - t₁ = 3.47 - 0.0028 = 3.467 s

5 0

3 years ago

Pls help me with this

katen-ka-za [31]

Answer:

needle -attract

wooden spoon -repel

nails -attract

safety pins -attract

paper -repel

Explanation:

7 0

2 years ago