Answer:
Explanation:
The inclined plane
An inclined plane consists of a sloping surface; it is used for raising heavy bodies. The plane offers a mechanical advantage in that the force required to move an object up the incline is less than the weight being raised (discounting friction). The steeper the slope, or incline, the more nearly the required force approaches the actual weight. Expressed mathematically, the force F required to move a block D up an inclined plane without friction is equal to its weight W times the sine of the angle the inclined plane makes with the horizontal (θ). The equation is F = W sin θ.
The lever
A lever is a bar or board that rests on a support called a fulcrum. A downward force exerted on one end of the lever can be transferred and increased in an upward direction at the other end, allowing a small force to lift a heavy weight.
The wedge
A wedge is an object that tapers to a thin edge. Pushing the wedge in one direction creates a force in a sideways direction. It is usually made of metal or wood and is used for splitting, lifting, or tightening, as in securing a hammer head onto its handle.
The wheel and axle
A wheel and axle is made up of a circular frame (the wheel) that revolves on a shaft or rod (the axle). In its earliest form it was probably used for raising weights or water buckets from wells.
Its principle of operation is best explained by way of a device with a large gear and a small gear attached to the same shaft. The tendency of a force, F, applied at the radius R on the large gear to turn the shaft is sufficient to overcome the larger force W at the radius r on the small gear. The force amplification, or mechanical advantage, is equal to the ratio of the two forces (W:F) and also equal to the ratio of the radii of the two gears (R:r)
Answer:
126.56 m
Explanation:
Applying,
-F = ma............. Equation 1
Where F = frictional force, m = mass of the car, a = acceleration.
Note: Frictional force is negative because it act in opposite direction to motion
But,
F = mgμ.......... Equation 2
Where g = acceleration due to gravity, μ = coefficient of friction
Substitute equation 2 in equation 1
-mgμ = ma
a = -gμ.............. Equation 3
From the question,
Given: μ = 0.735
Constant: 9.8 m/s²
Substitute these values in equation 3
a = -9.8×0.735
a = -7.203 m/s²
Finally,
Applying
v² = u²+2as.............. Equation 4
Where v = final velocity, u = initial velocity, s = distance
From the question,
Given: u = 42.7 m/s, v = 0 m/s (to a stop), a = -7.203 m/s²
Substitute these values into equation 4
0² = 42.7²+2(-7.203)s
-1823.29 = -14.406s
s = -1823.29/-14.406
s = 126.56 m
<span>(9 kg)(5 m/s^2) = M(3 m/s^2)
</span><span>that the acceleration of the object varies inversely with its mass.</span>
Answer:
Answer:
the amount of energy flowing is 1.008x10⁹J
Explanation:
To calculate how much heat flows, the expression is the following:
Where
K=thermal conductivity=0.81W/m°C
A=area=6.2*12=74.4m²
ΔT=30-8=22°C
L=thickness=8cm=0.08m
t=time=16.9h=60840s
Replacing:
Explanation:
Answer:
Later high school years and freshman year of college
Explanation:
The transition from high school to college is an important developmental milestone that holds the potential for personal growth and behavioral change. A cohort of 2,025 students was recruited during the summer before they matriculated into college and completed Internet-based surveys about their participation in a variety of behavioral risks during the last three months of high school and throughout the first year of college. Alcohol use, marijuana use, and sex with multiple partners increased during the transition from high school to college, whereas driving after drinking, aggression, and property crimes decreased. Those from rural high schools and those who elected to live in private dormitories in college were at highest risk for heavy drinking and driving after drinking.
