Answer:
1. The skater's kinetic energy decreases as he moves up the ramp. As the skater moves down the ramp, his potential energy decreases
2.Kinetic Energy is the energy of motion. As the skateboard rolls down the ramp it loses potential energy and gains kinetic energy. The total energy of the skateboarder remains constant.
Answer
1. 1cm=10mm, 1kg=1000g and 12in=1 ft
2. 50mm=5cm
48 in =4ft
36ft=12 yd
2.5m=250cm
1000mL= 1 L
Explanation
if 1cm=10mm then 5cm=?
5×10=50mm
if 12 in =1ft then 48in=?
48/12 =4 ft
if 1m=100cm, then 2.5m=?
2.5×100= 250cm
and when know from capacity that 1000mL is equivalent to 1 liter.
Using the law of constant proportions which says that within the same compound, elements exist in fixed ratios.
Therefore; we can use the ratio of total mass to the mass of carbon, to determine the amount of carbon in another sample.
Mass C / Mass CH4 = Mass C / Mass CH4
43.2 g / 57.6 g = Mass C / 37.8 g
Mass C = 37.8 g × 43.2 g / 57.6 g
= 28.35 g
Hence; the percentage of carbon will be;
=(28.35/ 37.8 )× 100%
= 75 %
Thus; 75% of 37.8 g of methane is carbon