Answer:
The car stops in 7.78s and does not spare the child.
Explanation:
In order to know if the car stops before the distance to the child, you take into account the following equation:
(1)
vo: initial speed of the car = 45km/h
a: deceleration of the car = 2 m/s^2
t: time
xo: initial distance to the child = 25m
x: final distance to the child = 0m
It is necessary that the solution of the equation (1) for time t are real.
You first convert the initial speed to m/s, then replace the values of the parameters and solve the quadratic polynomial for t:


You take the first value t1 because it has physical meaning.
The solution for t is real, then, the car stops in 7.78s and does not spare the child.
Answer:
positive
Explanation:
The ball is rolling down with a negative velocity, but the velocity is slowing down. therefore the velocity must increase in order for the ball to slow down.
For example let the ball's initial velocity be -15 m/s. and it is slowing down to let's say -13 m/s. Well this means that it's velocity has increase by 2 m/s. So, its acceleration is positive.
C. amphibian eggs do not contain a protective shell
Answer:
No getting rid of fossil fuel is not at all possible.
Explanation:
Dream of 100% renewable energy is possible through electrification and use of energy from sun, water and wind. Since, the high production cost of power plant for extracting energy from these sources in itself is a big challenge and hence decarbonized energy in current scenario is not realistic.
Answer:
1.False
2.4 E
Explanation:
1.We have to find the statement is true or false.
We know that
Time constant,
Time constant is inversely proportional to resistance R .It means when R increases then time constant decreases when R decrease then the time constant decreases.
Statement:The larger the value of R ,the longer it takes the circuit to reach its final steady- state value
It is false.
2.Energy stored in inductor,E=
When I'=2I
Then, 
Hence,the new total energy will become 4 E.