Answer:
The first law, also called the law of inertia, was pioneered by Galileo. This was quite a conceptual leap because it was not possible in Galileo's time to observe a moving object without at least some frictional forces dragging against the motion. In fact, for over a thousand years before Galileo, educated individuals believed Aristotle's formulation that, wherever there is motion, there is an external force producing that motion.
The second law, $ f(t)=m\,a(t)$ , actually implies the first law, since when $ f(t)=0$ (no applied force), the acceleration $ a(t)$ is zero, implying a constant velocity $ v(t)$ . (The velocity is simply the integral with respect to time of $ a(t)={\dot v}(t)$ .)
Newton's third law implies conservation of momentum [138]. It can also be seen as following from the second law: When one object ``pushes'' a second object at some (massless) point of contact using an applied force, there must be an equal and opposite force from the second object that cancels the applied force. Otherwise, there would be a nonzero net force on a massless point which, by the second law, would accelerate the point of contact by an infinite amount.
Explanation:
Easy ! EVERY element and every compound melts, then boils and becomes a gas, if you heat it to a high enough temperature. That includes iron, gold, water, salt, glass, almost any substance.
Answer:
8100W
Explanation:
Let g = 10m/s2
As water is falling from 60m high, its potential energy from 60m high would convert to power. So the rate of change in potential energy is
or 9000W
Since 10% of this is lost to friction, we take the remaining 90 %
P = 9000*90% = 8100 W
Answer:
B)
Explanation:
Negative (-) charge M will not move towards negative (-) charge K because, same charges will not attract each other in the given case
Negative (-) charge at the M tends to move towards positive (+) charge L in the direction of B) because opposite charges attract each other.
Answer:
the girl must sit 2 cm from the pivot at the opposite end of the seesaw.
Explanation:
Given;
length of the seesaw, L = 4.0 m
weight of the boy, W₁ = 400 N
position of the boy from the pivot, d₁ = 1.5 m
weight of her sister, W₂ = 300 N
First, make a sketch of this information given;
0---0.5m---------------------Δ--------------------------4m
↓<--------1.5m-------> <---------x--------->↓
400 N 300N
Apply the principle of moment about the pivot, to determine the value of x;
Sum of anticlockwise moment = sum of clockwise moment
400(1.5) = 300(x)
600 = 300x
x = 600/300
x = 2 cm
Thus, the girl must sit 2 cm from the pivot at the opposite end of the seesaw.
