<span>Answer:
skater x km/h
cyclist 20 faster x + 20 km/h
skater 30 km
cyclist 80 km
skater time = cyclist time
t=d/r
30 / x = 80 /( x + 20
cross multiply
30 ( x + 20 ) = 80 x
30 x + 600 = 80 x
30 x - 80 x = -600
-50 x = -600
/ -50
x = 12 km/h
12 km/h skater</span>
Answer:
Explanation:
Given
mass of children 
distance between two children 
suppose small child is at a distance of x m from pivot point
so torque of small child and heavier child must be equal
Answer:
Both, potential energy and kinetic energy depends on mass. The higher the mass, the higher the energy. However, the difference is that potential energy depends on vertical height whereas kinetic energy depends on the velocity.
Explanation:
From the formula we can see that;
Potential Energy = mass* gravitational acceleration *vertical height.
Kinetic Energy = 0.5 * mass * (velocity)^2
