Answer:
Option E is correct.
There must be a horizontal wind opposite the direction of the stone's motion, because ignoring air resistance when calculating the horizontal range would yield a value greater than 32 m.
Explanation:
Normally, ignoring air resistance, for projectile motion, the range (horizontal distance teavelled) of the motion is given as
R = (u² sin 2θ)/g
where
u = initial velocity of the projectile = 20 m/s
θ = angle above the horizontal at which the projectile was launched = 30°
g = acceleration due to gravity = 9.8 m/s²
R = (30² sin 60°) ÷ 9.8
R = 78.53 m
So, Normally, the stone should travel a horizontal distance of 78.53 m. So, travelling a horizontal distance of 32 m (less than half of what the range should be without air resistance) means that, the motion of the stone was impeded, hence, option E is correct.
There must be a horizontal wind opposite the direction of the stone's motion, because ignoring air resistance when calculating the horizontal range would yield a value greater than 32 m.
Hope this Helps!!!
Answer:
1.59 seconds
12.3 meters
but if you are wise you will read the entire answer.
Explanation:
This is a good question -- if not a bit unusual. You should try and understand the details. It will come in handy.
Time
<u>Given</u>
a = 0 This is the critical point. There is no horizontal acceleration.
d = 20 m
v = 12.6 m/s
<u>Formula</u>
d = vi * t + 1/2at^2
<u>Solution</u>
Since the acceleration is 0, the formula reduces to
d = vi * t
20 = 12.6 * t
t = 20 / 12.6
t = 1.59 seconds.
It takes 1.59 seconds to hit the ground
Height of the building
<u>Givens</u>
t = 1.59 sec
vi = 0 Another critical point. The beginning speed vertically is 0
a = 9.8 m/s^2 The acceleration is vertical.
<u>Formula</u>
d = vi*t + 1/2 a t^2
<u>Solution</u>
d = 1/2 a*t^2
d = 1/2 * 9.8 * 1.59^2
d = 12.3 meters.
The two vi's are not to be confused. The horizontal vi is a number other other 0 (in this case 12.6 m/s horizontally)
The other vi is a vertical speed. It is 0.
<u>C</u> is the correct answer, because energy cannot be created neither destroy. The energy is changing from chemical to from electric to light, and from light to heat.
Sorry if you get this wrong but I believe it’s C because without inertia.. particles will fall apart because inertia keeps everything together in the same motion
