Answer:
a) t = 2.55s
b) [tex]v_{0x} = 9.80 m/s[/tex]
c) yes
Explanation:
In order to solve this problem, we can start by drawing a sketch of the situation so we can better visualize what the problem is about (see attached picture).
a)
For the first question. We are talking about a movement in two dimensions. So on the first question they are asking us for vertical movement. It will be uniformly accelerated, so we can use the following formula:
[tex]y_{f}=y_{0}+V_{0y}t+\frac{1}{2}at^{2}[/tex]
We know the following:
[tex]y_{f}=0[/tex]
[tex]y_{0} = 32m[/tex]
[tex]V_{0y}=0[/tex]
t=?
[tex]a=-9.81 m/s ^{2}[/tex]
With this data, we can simplify our equation, so we end up with:
[tex]y_{0}+\frac{1}{2}at^{2}=0[/tex]
so we can now substitute the data we know and solve for t:
[tex]32m-\frac{1}{2}(9.81 m/s^{2})t^{2}=0[/tex]
[tex](-4.905 m/s^{2})t^{2}=-32m[/tex]
[tex]t^{2} = \frac{-32m}{-4.905 m/s^{2}}[/tex]
[tex]t=\sqrt{6.52s^{2}}[/tex]
t = 2.55 s
b)
For part b, since we are talking about horizontal movement and we are neglecting drag, this means that his horizontal speed will be constant. So we can use the following formula:
[tex]V_{x}=\frac{x}{t}[/tex]
we know he most move a horizontal distance of 25 meters in a time of 2.55s so we get:
[tex]V_{x} = \frac{25m}{2.55s}[/tex]
[tex]V_{x}=9.80 m/s[/tex]
c) for part c, we can do the conversion between miles per hour to meters per second like this:
[tex]\frac{27mi}{1hr}*\frac{1hr}{3600s}*\frac{5280ft}{1mi}*\frac{0.3048m}{1ft}[/tex]
so the given initial speed is equivalent to:
12.07 m/s
this is greater than the minimum 9.80 m/s we need, so the skater will clear the pool at this speed.
(a) The time spent in air by the skateboarder is 2.56 s
(b) The initial speed needed by the skateboarder to clear the pool is 9.77 m/s.
(c) The skateboarder with given initial speed of 27 mph will clear the pool since it is greater than minimum initial velocity required.
The given parameters;
width of the pool, d= 25 mheight of the building, h = 32 mThe time spent in air by the skateboarder is calculated as follows;
[tex]h = v_0t + \frac{1}{2} gt^2\\\\h = 0 + \frac{1}{2} gt^2\\\\gt^2 = 2h\\\\t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2\times 32}{9.8} } \\\\t =2.56 \ s[/tex]
The initial speed needed by the skateboarder to clear the pool is calculated as;
[tex]v = \frac{d}{t} \\\\v = \frac{25}{2.56} \\\\v = 9.77 \ m/s[/tex]
The initial speed of the skateboarder is m/s;
[tex]27 \ \frac{mile}{hour} \times \frac{1609.3 \ m}{1 \ mile} \times \frac{1 \ hr}{3600 \ s} = 12.07 \ m/s[/tex]
Thus, the skateboarder with given initial speed of 27 mph will clear the pool since it is greater than minimum initial velocity required.
Learn more here:https://brainly.com/question/14670531
PLEASE HELP URGENT 1. You put 1 gram of salt into 1 liter of water and stir. The resulting liquid is an example of
A. A pure substance.
B. a homogeneous mixture.
C. a heterogeneous mixture.
D. an immiscible mixture.
Which of the following is not an example of acceleration?
A) A person jogging at 3 m/s along a winding path
B) A car stopping at stop sign
C) A cheetah running 27 m/s east
D) a plane taking off
Clara's grandfather is a captain of a cargo ship. He prefers to navigate his ship through the moderate neap tides. At these times, the line between Earth and the sun is at a right angle to the line between Earth and the moon. Which phase or phases of the moon describe this alignment?
Answer:
The phases are the first and third quarters.
Explanation:
During the first quarter of the moon phases, the line between Earth and the Sun is at a right angle to the line between Earth and the moon. At this time the moon has completed the first quarter of its orbit around the earth. At this point, half of the moon is fully reflecting light from the sun.
Also during the third quarter which is the last quarter, the line between the earth and the sun is at a right angle to the line between the earth and the moon. This is the time when the second half of the moon which was not illuminated during the first quarter becomes completely illuminated.
A Red-Tailed Hawk leaves its nest and flies 100.0 meters across the sky in 20 seconds, when it spots a garter snake on the ground below. It then flies 50.0 meters in 5.0 seconds to catch the snake. What was the hawk's average speed over his entire journey?
Answer:
7.5 m/s
Explanation:
A red tailed hawk leaves its nest and flies 100 meters across the sky in 20 secs
Speed 1= distance/time
= 100/20
= 5m/s
When it spots a garter snake on the ground it flies 50 meters in 5 secs
Average speed= distance /time
= 50/5
= 10 m/s
Therefore the average speed of the hawk over the entire journey can be calculated as follows
= 10+5/2
= 15/2
= 7.5 m/s