Average speed = (total distance) / (total time)
First segment:
15 m/s for 10 sec; distance covered = (15 x 10) = 150 m
Second segment:
20 m/s for 20 sec; distance covered = (20 x 20) = 400 m
Third segment:
30 m/s for 15 sec; distrance covered = (30 x 15) = 450 m
Total time = (10s + 20s + 15s) = 45 sec
Total distance = (150m + 400m + 450m) = 1,000 m (1 km)
<em>Average speed</em> = (1,000 m) / (45 sec) = <em>22.22 m/s</em>
Explanation:
The balanced chemical equation is given as:
2H₂O₂ → O₂ + 2H₂O
А There are two peroxide molecules on the reactant side.
The statement is correct because the left hand side is the reactant side. We can read the reaction as;
2 molecules of hydrogen peroxide decomposed to given 1 molecule of oxygen gas and 2 molecules of water .
D Mass must be conserved so there are an equal number of molecules in the reactants and products.
E Mass must be conserved so there are an equal number of atoms in the reactants and products.
Since the chemical equation is balanced, choices D and E are correct. The reaction will have equal number of molecules and atoms on both sides of the expression.
if for a force of 0.5 N we have a displacement of -0.02m we can calculate the elastic constant(k) with the formula F=-kx(F=0.5N x=-0.02)
k=F/x k=0.5/0.02=25N/m
now we can calculate the period by the formula
T=2π√(m/k)
in the mass we convert grams to kilograms so 100g=0.1kg
T=6.28√(0.1/25)⇒T=0.39seconds
The main function of the cardiovascular system is therefore to maintain blood flow to all parts of the body, to allow it to survive. Veins deliver used blood from the body back to the heart.
Answer:
Explanation:
Energy stored in spring = 1/2 k x²
80 = 1/2 x k .2²
k = 4000 N /m
Required force = k x
= 4000 x .2
=800 N
b )
Additional work done
= difference in stored elastic energy
= 1/2 k ( x₂² - x₁² )
= .5 x 4000 ( .4² - .2² )
= 240 J
