Answer:
Explanation:
First we have to find the time required for train to travel 60 meters and impact the car, this is an uniform linear motion:
The reaction time of the driver before starting to accelerate was 0.50 seconds. So, remaining time for driver is 1.5 seconds.
Now, we have to calculate the distance traveled for the driver in this 0.5 seconds before he start to accelerate. Again, is an uniform linear motion:
The driver cover 10 meters in this 0.5 seconds. So, the remaining distance to be cover in 1.5 seconds by the driver are 35 meters. We calculate the minimum acceleration required by the car in order to cross the tracks before the train arrive, Since this is an uniformly accelerated motion, we use the following equation:
The masses are equal.
According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
I hope that this helps you!
Answer:
The current doubles
Explanation:
In a circuit, Ohm's law gives the relationship between voltage, current and resistance:
where
V is the voltage
R is the resistance
I is the current
In this problem,
V is held constant
R is halved:
Therefore, the new current is
So, the current doubles.
Answer:
Explanation:
For this problem, we need to make use of Newton's law of universal gravitation. This law states that two objects attract each other with a force that is inversely proportional to the square of the distance of their centers of mass and directly proportional to the product of their masses. We can write this as:
where F is the attractive force, G is the gravitational constant, r is the distance between their centers of mass, and M and m are the masses of the objects.
From here we will let M be the mass of the earth, and m the mass columbia. From Newton's second law, we know that the gravitational force exerted to columbia due to the earth can be written as
,
here, making a substitution we get
The distance between columbia and the earth's center is
.
Now, computing the acceleration:
The best way to find that you want is the line fit. When acceleration is constant the speed(v) changes smoothly every moment, so the v line must be straight. Differently, the accelaration changes.