The answer is B.It decreases the change of the momentum of the person
The Wheel & Axle. The wheel has always been considered a major invention in the history of mankind
The Inclined Plane
The Wedge
The Pulley
The Screw
<span>2700 Joules
The important value here is how high the escalator moved you. The actual length doesn't matter. All it affects is how fast the work is performed upon you. So the escalator lifted 64 kg against gravity for 4.3m. So:
4.3 m * 9.8 m/s^2 * 64 kg = 2696.96 kg*m^2/s^2 = 2696.96 Joules
Rounding to 2 significant figures gives 2700 Joules</span>
Answer:
200 million years
Explanation:
The equation that describes the decay of a radioactive isotope is
where
is the amount of radioactive isotope left at time t
is the initial amount of isotope
is the half-life of the sample
In this problem, the ratio between unstable isotope and daughter isotope is 1:15; this means that
Because the "total proportion" of original sample was 1+15=16.
Also we know that the half-life is
So we can re-arrange the equation to find t, the age of the rock:
So, 200 million years.
Answer:
Explanation:Advatages
1..Its takes precise reading accurate
2. it is moveable because of its small weight
3.It is easy to read and can be kept inside water
Disadvantages
1. It breaks easily because of its small size
2. If broken there can be risk of exposure to mercury chemicals.
