A dog travels 18 meters south across the backyard in 11 seconds. What is the dog's speed?

Which two statements best determine whether an engineering design is

pshichka [43]

Answer: A and B

Explanation:

just took the apex test

7 0

3 years ago

Dr. John Paul Stapp was U.S. Air Force officer who studied the effects of extreme deceleration on the human body. On December 10

Mars2501 [29]

Answer:

a) $a=5.7551 \times g$

b) $d=20.5539\times g$

Explanation:

Given:

speed of rocket initially, $v_i=0\ m.s^{-1}$

top speed of rocket after acceleration, $v=282\ m.s^{-1}$

time taken to get to the top speed, $t_i=5\ m.s^{-1}$

final speed of the rocket, $v_f=0\ m.s^{-1}$

time taken to get to the final speed after reaching the top speed, $t_f=1.4\ s$

Now the acceleration:

$a=\frac{v-v_i}{t_i}$

$a=\frac{282-0}{5}$

$a=56.4\ m.s^{-2}$

Now as a fraction of gravity:

$a=\frac{56.4}{9.8}\times g$

$a=5.7551 \times g$

Now, the deceleration:

$d=\frac{0-282}{1.4}$

$d=201.4285\ m.s^{-2}$

Now as a fraction of gravity:

$d=\frac{201.4285}{9.8}\times g$

$d=20.5539\times g$

6 0

3 years ago

Dwayne ‘The Rock’ Johnson needs to escape from the fourth floor of a burning building (in a movie). He ties a rope around his wa

ZanzabumX [31]

Answer:

Final Speed of Dwayne 'The Rock' Johnson = 15.812 m/s

Explanation:

Let's start out with finding the force acting downwards because of the mass of 'The Rock':

Dwayne 'The Rock' Johnson: 118kg x 9.81m/s = 1157.58 N

Now the problem also states that the kinetic friction of the desk in this problem is 370 N

Since the pulley is smooth, the weight of Dwayne Johnson being transferred fully, and pulls the desk with a force of 1157.58 N. The frictional force of the desk is resisting this motion by a force of 370 N. Subtracting both forces we get the resultant force on the desk to be: 1157.58 - 370 = 787.58 N

Now lets use F = ma to calculate for the acceleration of the desk:

787.58 = 63 x acceleration

acceleration = 12.501 m/s

Finally, we can use the motion equation:

$v^2 - u^2 = 2*a*s$

here u = 0 m/s (since initial speed of the desk is 0)

a = 12.501 m/s

and s = 10 m

Solving this we get:

$v^2 - 0 = 2 * 12.501 * 10$

$v = 15.812 m/s$

Since the desk and Mr. Dwayne Johnson are connected by a taught rope, they are travelling at the same speed. Thus, Dwayne also travels at 15.812 m/s when the desk reaches the window.

5 0

3 years ago

I start going 10 m/sIf I slow down at 2 m/s/s how far will I go before I stop

klasskru [66]

Answer:

25 m

Explanation:

Given:

v₀ = 10 m/s

v = 0 m/s

a = -2 m/s²

Find: Δx