Explanation:
In order to find out if the keys will reach John or not, we can use the formula of projectile motion to find the maximum height reached by the keys:
H = V²Sin²θ/2g
where,
V = Launch Speed = 18 m/s
θ = Launch Angle = 40°
g = 9.8 m/s²
Therefore,
H = (18 m/s)²[Sin 40°]²/(2)(9.8 m/s²)
H = 6.83 m
Hence, the maximum height that can be reached by the projectile or the keys is greater than the height of John's Balcony(5.33 m).
Therefore, the keys will make it back to John.
The gravitational force exerted by the earth on a person standing on the earth's surface is 602.74 N.
<h3>What is the gravitational force of the earth on the person?</h3>
The gravitational force exerted by the earth on a person standing on the earth's surface is given below as follows:
where
G = 6.67 * 10⁻¹¹
m¹ = 62 kg
m² = 5.97 * 10²⁷ kg
r = 6.4 * 10⁶ m

Therefore, the gravitational force exerted by the earth on a person standing on the earth's surface is 602.74 N.
Learn more about gravitational force at: brainly.com/question/940770
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Answer:
Her speed is 9.8 meter per second
Explanation:
Newton's second law states that acceleration (a) is related with force (F) by:
(1)
Here the only force acting on the firefighter is the weight F=mg so (1) is:
Solving for a:

Now with the acceleration we can use the Galileo's kinematic equation:
(2)
With Vf the final velocity, Vo the initial velocity and Δx the displacement, because the firefighter stars from rest Vo=0 so (2) is:

Solving for Vf


Answer:
Electric Current
Explanation:
The flow (or free movement) of these electrons through a wire.
Pretty sure :)
The answer should be flammability