<span>One thing that radio waves, microwaves, light, and x-rays all have in common is that they are all forms of electromagnetic waves.</span>
Answer:
D
Explanation:
Because kinetic energy do have more than potential energy: kinetic energy is when a object is moving. Potential energy is when something is at rest and has no movement what so ever
Answer:
6.575
Explanation:
T1 = 30C = 30 + 273 = 303 K
T2 = - 10 C = - 10 + 273 = 263 K
The coefficient of performance of heat pump
k = T2 / (T1 - T2)
k = 263 / (303 - 263) = 6.575
The law applied here is Hooke's Law which describes the force exerted by the spring with a given distance. The equation for this is F = kΔx, where F is the force in Newtons, k is the spring constant in N/m while Δx is the displacement in meters.
If you want to find work done by a spring, this can be solved by using differential equations. However, derived equations are already ready for use. The equation is
W = k[{x₂-x₁)² - (x₁-xn)²],
where
xn is the natural length
x₁ is the stretched length
x₂ is also the stretched length when stretched even further than x₁
In this case xn =x₁. So, that means that (x₁-xn) = 0 and (x₂-x₁) = 11 cm or 0.11 m.
Then, substituting the values,
2 J = k (0.11² -0²)
k = 165.29 N/m
Finally, we use the value of k to the Hooke's Law to determine the Force.
F = kΔx = (165.29 N/m)(0.11 m)
F = 18.18 Newtons
Running on sand requires 1.6 times more energy spent than running on hard surface, so the force applied by our foot on sand is less.
