The answer is
A. Yes, the obtained speed is less than the world record
The explanation:
when the obtained speed is 6 m /s
and the world record speed = distance / time = 100 m / 10 s = 10 m/s
So, Yes, the obtained speed is less than the world record
Not only is it less, its also a reasonable average speed for a somewhat athletic person. Therefore, the leap is entirely possible.
-Samuel Brady gained his lasting notoriety for his leap over the Cuyahoga River around 1780 in what is now Kent, Ohio. After following a band of Indians into the Ohio country, a failed ambush attempt resulted in the band chasing Brady near the Cuyahoga River. To avoid capture, Brady leaped across a 22-foot (6.7 m) wide gorge of the river (which was widened considerably in the 1830s for construction of the Pennsylvania and Ohio Canal) and fled to a nearby lake where he hid in the water under a fallen tree using a reed for air.
Part (a): The minimum speed of Brady should be [tex]\boxed{6\text{ m/s}}[/tex] to cross the cliff.
Part (b): The speed of Brady’s leap is possible to achieve, as it is less than the speed of world record.
Further Explanation:
(a)
Brady jumps from a cliff to go on other side. He crosses [tex]22\text{ ft}[/tex] horizontal distance from a height of [tex]20\text{ft}[/tex]. To jump from cliff, he follows the Newton’s law of motion.
Given:
The horizontal distance is [tex]22\text{ ft}[/tex].
The vertical distance is [tex]20\text{ft}[/tex].
Concept:
The horizontal distance in meter is [tex]6.71\text{ m}[/tex].
The vertical distance in meter is [tex]6.10\text{ m}[/tex].
To obtain the time of flight, applying one of the equation of motion given as:
[tex]s=ut+\dfrac{1}{2}at^2[/tex]
Substitute [tex]0\text {m/s}[/tex] for [tex]u[/tex] and rearrange the above equation for [tex]t[/tex] :
[tex]t=\sqrt{\dfrac{2s}{a} }[/tex]
Substitute [tex]6.10\text{ m}[/tex] for [tex]s[/tex] and [tex]9.81\text{ m}/\text{s}^2[/tex] for [tex]a[/tex] in above equation.
[tex]\begin{aligned}t&=\sqrt{\dfrac{2\times6.10}{9.81}}\text{ s}\\&=1.12\text{ s}\end{aligned}[/tex]
The time of flight and time taken to cover horizontal distance are equal.
Horizontal velocity of Brady given as:
[tex]\begin{aligned}v&=\dfrac{6.71}{1.12}\text{ m/s}\\&\approx6\text{ m/s}\end{aligned}[/tex]
Thus, the minimum speed of Brady should be [tex]\boxed{6\text{ m/s}}[/tex] to cross the cliff.
(b)
The minimum speed with which Brady is running is [tex]6\text{ m/s}[/tex].
The speed of world record given as:
[tex]\begin{aligned}V&=\frac{100}{10}\text{ m/s}\\&=10\text{ m/s}\end{aligned}[/tex]
Thus, the speed of Brady’s leap is possible to achieve, as it is less than the speed of world record.
Learn more:
1. Projectile motion of a body: https://brainly.com/question/11023695
2. Body in pure rolling motion: https://brainly.com/question/9575487
3. Newton’s law of motion: https://brainly.com/question/6125929
Answer Details:
Grade: High School
Subject: Physics
Chapter: Kinematics
Keywords:
1780, Brady's Leap, Captain, Sam, U.S. Continental Army, horizontally, cliff, Ohio's Cuyahoga, gorge, leap, 22 ft, 20 ft, minimum, speed, river, 100 m, dash, 10 s, jump, time of flight, vertical and distance.
