Answer:
45 s
Explanation:
To find the time it takes to stop, we first find the deceleration, a of the car from
v² = u² + 2as and a = (v² - u²)/2s were v = final velocity of car = 0 mph = 0 m/s, u = initial velocity of car = 30 mph = 30 × 1609.34 ft ÷ 3600 s = 13.41 ft/s and s = distance = 300 ft. Substituting the values into a, we ave
a = (v² - u²)/2s = (0² - 13.41²)/2×300 = -0.3 ft/s²
We then find the time for this deceleration from v = u + at ⇒ t = (v - u)/a
t = (v - u)/a = (0 - 13.41 ft/s)/-0.3 ft/s² = - 13.41 ft/s/-0.3 ft/s² = 44.7 s ≅ 45 s
So it takes 45 seconds to stop.
Answer:
Correct answer: Cf = tan 33° = 0.649 (I guess you meant degrees and not minutes)
Explanation:
The horizontal component of the object's weight equals to the force of friction and the object is just about to slide.
The horizontal component of the object's weight is Qh = mg sin 33°
The force of friction is Ffr = Cf · Qv = Cf · mg cos 33° , where Cf is the coefficient of static friction and Qv vertical component of the object's weight
Qh - Ffr = 0 => Qh = Ffr => mg sin 33° = Cf mg cos 33°
we divide both sides of the equation by mg and get:
Cf · cos 33° = sin 33° => Cf = sin 33° / cos 33° = tan 33° = 0.649
Cf = 0.649 the weight of the object is unnecessary data
God is with you!!!
Answer: 1175 J
Explanation:
Hooke's Law states that "the strain in a solid is proportional to the applied stress within the elastic limit of that solid."
Given
Spring constant, k = 102 N/m
Extension of the hose, x = 4.8 m
from the question, x(f) = 0 and x(i) = maximum elongation = 4.8 m
Work done =
W = 1/2 k [x(i)² - x(f)²]
Since x(f) = 0, then
W = 1/2 k x(i)²
W = 1/2 * 102 * 4.8²
W = 1/2 * 102 * 23.04
W = 1/2 * 2350.08
W = 1175.04
W = 1175 J
Therefore, the hose does a work of exactly 1175 J on the balloon
Answer:
A) An interference pattern
Explanation:
the two slit experiment is key to understand the microscopic world. The wave-like properties of light were demonstrated by the famous experiment first performed by Thomas Young in the early nineteenth century. In original experiment, a point source of light illuminates two narrow adjacent slits in a screen, and the image of the light that passes through the slits is observed on a second screen.
<u>Key Points</u>
- waves can interfere, for light this will make a series of light and dark bands
- matter particles, such as electrons, also produce interference patterns due to their wave-like nature
- so with a high flux of either photons or electrons, the characteristic interference pattern is visible
Answer:
[Speed] or [Velocity (if there is a direction)]