Answer:
3.25 seconds
Explanation:
It is given that,
A person throws a baseball from height of 7 feet with an initial vertical velocity of 50 feet per second. The equation for his motion is as follows :

Where
s is the height in feet
For the given condition, the equation becomes:

When it hits the ground, h = 0
i.e.

It is a quadratic equation, we find the value of t,
t = 3.25 seconds and t = -0.134 s
Neglecting negative value
Hence, for 3.25 seconds the baseball is in the air before it hits the ground.
pavement is defined as the surface of Road or sidewalk.
for example, the surface of Expressway.
There are two types of pavement.
rigid pavement which consists of one layer.
flexible pavement which consist of multiple layers.
While driving on roads of rural areas, if our right wheel moves off the pavement, we should always hold the steering wheel firmly and then take our foot off the pedal, then apply brake lightly until we are moving at a low speed.
if you run off the pavement, you should: turn the steering wheel quickly toward the road steer straight and slow down before attempting to return to the pavement steer straight ahead and speed up apply the brakes hard
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Answer:
The speed of molecule decreases and temperature also decreases
Explanation:
Kinetic energy of the molecules of a subsance is directly proportional to the temperature of molecule So as the kinetic energy decrease, temperature also decreases. decreses their speed.
Answer:
600Hz
Explanation:
In electrical systems of alternating current, the harmonics are, as in acoustics, frequencies multiples of the fundamental working frequency of the system and whose amplitude decreases as the multiple increases. For example, if we have systems fed by the 50 Hz network, harmonics of 100, 150, 200, etc. may appear.
In our case having a fundamental wave of 100Hz, I can have harmonics of 200,300,400, ..., 600Hz
Given the time, the final velocity and the acceleration, we can calculate the initial velocity using the kinematic equation A:

A skateboarder flies horizontally off a cement planter. After a time of 3 seconds (Δt), he lands with a final velocity (v) of −4.5 m/s. Assuming the acceleration is -9.8 m/s² (a), we can calculate the initial velocity of the skateboarder (v₀) using the kinematic equation A.

Given the time, the final velocity and the acceleration, we can calculate the initial velocity using the kinematic equation A:

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