Answer:
117.6 m/s downward
Explanation:
The penny is moving with uniform accelerated motion (free fall motion), so we can find its vertical velocity at time t with the following suvat equation:
v = u + at
where
v is the velocity at time t
u is the initial velocity
a is the acceleration
The penny starts at rest, so
u = 0
Also, the acceleration is the acceleration of gravity,
where we have chosen upward as positive direction, so the acceleration is negative, since it is downward.
Substituting t = 12 s, we find the velocity of the penny when it hits the ground:
downward, since the sign is negative.
Burning is a chemical change because when your burning something your releasing chemicals into the air ( turning it into gas , like CO2) , it requires more energy to break chemical bonds. Melting/bending your just changing the physical look of object, boiling your just heating it but the make up of the object is still the same.
Complete Question
A 100-W (watt) light bulb has resistance R=143Ω (ohms) when attached to household current, where voltage varies as V=V0sin(2πft), where V0=110 V, f=60 Hz. The power supplied to the bulb is P=V2R J/s (joules per second) and the total energy expended over a time period [0,T] (in seconds) is
Compute U if the bulb remains on for 5h
Answer:
The value is
Explanation:
From the question we are told that
The power rating of the bulb is
The resistance is
The voltage is
The energy expanded is
The voltage
The frequency is
The time considered is
Generally power is mathematically represented as
=>
=>
So
=>
=>
=>
=>
=>
=>
<h3><u>
For the aceleration:</u></h3>
First, let's find the resultant, and <u>applicate 2nd law of Newton</u> using the resultant, so:
R = ma
F - Ff = ma
Data:
F = Force = 1150 N
Ff = Friction force = 490 N
m = Mass = 150 kg
a = Aceleraction = ?
Replacing according our data:
1150 N - 490 N = 150 kg * a
660 N = 150 kg * a
660 N / 150 kg = a
a = 4,4 m/s² ← Aceleration of the object
<h3><u>For the normal force:</u></h3>
The normal force IS NOT the resultant force, the normal force's the force between the ground and the object, in another words, is the weight of the object, and for the weight:
w = mg
w = 150 kg * 10 m/s²
w = 1500 N ← Normal force between object and ground.
Shaking the ground up and down back and forth perpendicular to the direction it is traveling