In the problems, please assume the free-fall acceleration $g=9.80 \mathrm{m} / \mathrm{s}^{2}$ unless a more precise value is given in the problem statement. Ignore air resistance. A cheetah can accelerate from rest to \(24 \mathrm{m} / \mathrm{s}\) in $2.0 \mathrm{s}$ Assuming the acceleration is constant over the time interval, (a) what is the magnitude of the acceleration of the cheetah? (b) What is the distance traveled by the cheetah in these \(2.0 \mathrm{s} ?\) (c) A runner can accelerate from rest to \(6.0 \mathrm{m} / \mathrm{s}\) in the same time, $2.0 \mathrm{s} .$ What is the magnitude of the acceleration of the runner? By what factor is the cheetah's average acceleration magnitude greater than that of the runner?

Short Answer

Expert verified
Answer: The cheetah's acceleration is 4 times greater than that of the runner.

Step by step solution

01

(a) Calculate the cheetah's acceleration magnitude.

We can use the formula $$a = \frac{v - u}{t}$$ where \(a\) is acceleration, \(v\) is final velocity, \(u\) is initial velocity, and \(t\) is time. For the cheetah, the initial velocity is 0 (rest), the final velocity is 24 m/s, and the time interval is 2.0 s. So, we have: $$a = \frac{24-0}{2.0}$$ $$a = 12 \,\text{m/s}^2$$ The magnitude of the acceleration of the cheetah is 12 m/s².
02

(b) Calculate the distance traveled by the cheetah.

One of the kinematic equations is: $$s = ut + \frac{1}{2}at^2$$ where \(s\) is distance, \(u\) is initial velocity, \(t\) is time, and \(a\) is acceleration. For the cheetah, initial velocity is 0, time is 2.0 s, and acceleration is found to be 12 m/s². So, we have: $$s = 0(2.0) + \frac{1}{2}(12)(2.0)^2$$ $$s = 24 \,\text{m}$$ The distance traveled by the cheetah in 2.0 s is 24 m.
03

(c) Calculate the runner's acceleration and cheetah's acceleration magnitude compared to the runner's.

Using the same acceleration formula as before: $$a' = \frac{v' - u'}{t'}$$ Where \(a'\), \(v'\), \(u'\) and \(t'\) are the acceleration, final velocity, initial velocity, and time, respectively, for the runner. The initial velocity is 0 (rest), the final velocity is 6.0 m/s, and the time interval is 2.0 s. So we have: $$a' = \frac{6.0 - 0}{2.0}$$ $$a' = 3 \,\text{m/s}^2$$ The magnitude of the acceleration of the runner is 3 m/s². To find the factor by which the cheetah's average acceleration magnitude is greater than that of the runner, divide the magnitude of the cheetah's acceleration by the magnitude of the runner's acceleration: $$ \text{Factor} = \frac{a}{a'} = \frac{12}{3} = 4 $$ The cheetah's average acceleration magnitude is 4 times greater than that of the runner.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

If a car traveling at \(28 \mathrm{m} / \mathrm{s}\) is brought to a full stop in \(4.0 \mathrm{s}\) after the brakes are applied, find the average acceleration during braking.
A runner, jogging along a straight line path, starts at a position $60 \mathrm{m}$ east of a milestone marker and heads west. After a short time interval he is \(20 \mathrm{m}\) west of the mile marker. Choose east to be the positive \(x\) -direction. (a) What is the runner's displacement from his starting point? (b) What is his displacement from the milestone? (c) The runner then turns around and heads east. If at a later time the runner is \(140 \mathrm{m}\) east of the milestone, what is his displacement from the starting point at this time? (d) What is the total distance traveled from the starting point if the runner stops at the final position listed in part (c)?
A car is speeding up and has an instantaneous velocity of $1.0 \mathrm{m} / \mathrm{s}\( in the \)+x\( -direction when a stopwatch reads \)10.0 \mathrm{s} .$ It has a constant acceleration of \(2.0 \mathrm{m} / \mathrm{s}^{2}\) in the \(+x\) -direction. (a) What change in speed occurs between \(t=10.0 \mathrm{s}\) and \(t=12.0 \mathrm{s} ?(\mathrm{b})\) What is the speed when the stopwatch reads \(12.0 \mathrm{s} ?\)
please assume the free-fall acceleration \(g=9.80 \mathrm{m} / \mathrm{s}^{2}\) unless a more precise value is given in the problem statement. Ignore air resistance. Superman is standing \(120 \mathrm{m}\) horizontally away from Lois Lane. A villain throws a rock vertically downward with a speed of $2.8 \mathrm{m} / \mathrm{s}\( from \)14.0 \mathrm{m}$ directly above Lois. (a) If Superman is to intervene and catch the rock just before it hits Lois, what should be his minimum constant acceleration? (b) How fast will Superman be traveling when he reaches Lois?
please assume the free-fall acceleration \(g=9.80 \mathrm{m} / \mathrm{s}^{2}\) unless a more precise value is given in the problem statement. Ignore air resistance. During a walk on the Moon, an astronaut accidentally drops his camera over a 20.0 -m cliff. It leaves his hands with zero speed, and after \(2.0 \mathrm{s}\) it has attained a velocity of \(3.3 \mathrm{m} / \mathrm{s}\) downward. How far has the camera fallen after \(4.0 \mathrm{s} ?\)
See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free