I'm giving out a lot of points for whoever helps me and answers correctly! 3 questions to answer! Please answer them ALL!!! :D1 - Which of these is a good example of Newton's First Law of inertia?
A) A ball sits motionless on the ground
B) A ball gathers speed as it rolls downhill
C) A ball accelerates as it falls out of a classroom window
D) A ball returns to your hand after you throw it up in the air
2 - The space shuttle is located exactly half way between the earth and the moon. Which statement is true regarding the gravitational pull on the shuttle?
A) The moon pulls more on the shuttle
B) The earth pulls more on the shuttle
C) Both are equal due to equal distances
D) Both are equal due to the mass of the shuttle
3 - In which situation is the acceleration of the car negative?
A) The velocity of the car was 75/h over 4 hours
B) The velocity of the car reduced from 50 km/h to 35 km/h over one minute
C) The velocity of a car increased from 40 km/h to 75 km/h over 15 minutes
D) The velocity of a car was 45 km/h at 2:00 pm and at 4:00 pm the velocity of the car was 85 km/h
Answers
1. A) A ball sits motionless on the ground
Newton's First Law of inertia states that:
"When the forces acting on an object are balanced, the object stays at rest (if it was at rest) or continues its motion with constant velocity (if it was in motion)"
Among the options given, we see that the option
A) A ball sits motionless on the ground
is an example of this law: in fact, the ball sits at rest on the ground, the forces acting on it are balanced, so the ball stays at rest.
2. B) The earth pulls more on the shuttle
The gravitational attraction exerted by a planet on the shuttle is given by
where
G is the gravitational constant
M is the mass of the planet
m is the mass of the shuttle
r is the distance between the shuttle and the planet
In this problem, we are comparing the gravitational pulls exerted by the Earth and the Moon on the shuttle. The distance, r, is the same (because the shuttle is half-way), the mass of the shuttle m is the same, and G is the same. However, the mass of the Earth is greater than the mass of the Moon, so in the formula M is greater for the Earth: therefore, the Earth pulls more on the shuttle.
3. B) The velocity of the car reduced from 50 km/h to 35 km/h over one minute
The acceleration of the car is defined as the ratio between the change in velocity and the time taken:
where vf is the final velocity, vi is the initial velocity, and is the time taken.
In order to have a negative acceleration, the numerator must be negative: this means that the initial velocity, vi, must be greater than the final velocity, vf, and this situation occurs in option B), since the initial velocity is 50 km/h while the final velocity is 35 km/h.
1-a 2-b 3-b
srry had to write more, i go to this school
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Answers
Power, as you should have learned in your class, is a rate; it needs to be multiplied by time to get the amount of energy
Thus, your answer...time.
To calculate power, divide the amount of energy transferred by time.
Final answer:
Power in physics is the rate of energy transferred per unit time. It can be calculated by dividing the amount of energy transferred by the time required for the transfer.
Explanation:
In Physics, power is defined as the rate of transferring energy or the amount of energy per unit time. If you want to calculate the power, you take the amount of energy transferred and divide it by the time it takes for that transfer to occur. For example, if a light bulb transfers 100 joules of energy over 10 seconds, the power would be 100 joules divided by 10 seconds, which equals to 10 watts.
Learn more about Power here:
#SPJ2
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Answer:
Seven
Explanation:
Because all halogens have seven valence electrons, they are “eager” to gain one more electron. Doing so gives them a full outer energy level, which is the most stable arrangement of electrons. Halogens often combine with alkali metals in group 1 of the periodic table.
Answer:
Halogens only need one electron to complete their valkance shells.
Explanation:
Halogens are present in the VIIA group of the periodic table so seven electrons are already present. one is needed to become stable.
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a parachute has a cupping effect where it can only take so much, so it slows down your descendence
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radio waves bc they have the longest wave lenthgs in a magnetic spectrum