Answer:
Explanation:
Change in length of spring = 2.13 m
Component of weight acting on spring = mg sinθ
so
mg sinθ = k x where k is spring constant and x is total stretch due to force on the spring.
Here x = 2.13
mg sin17 = k x 2.13
31 x 9.8 sin17 = k x 2.13
k = 41.7 N/m
b ) In case surface had friction , spring would have stretched by less distance .
It is so because , the work done by gravity in stretching down is stored as potential energy in spring . In case of dissipative force like friction , it also takes up some energy in the form of heat etc so spring stretches less.
The net force will point towards the acceleration of the object, as supported by Newton's second law.
Relative density, or specific gravity, is the ratio of the density of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest; for gases, the reference is air at room temperature.
Answer:
1) energy = 15.6 kWh, 2) total_cost = $ 2.03
Explanation:
1) The energy dissipated is the product of the power and the time of use In a month it was used t = 6.5 h and the power of the toaster is
P = 2400 W = 2,400 kW
energy = P t
energy = 2,400 6.5
energy = 15.6 kWh
using rounding to a decimal
energy = 15.6 kWh
2) The cost of energy is unit_cost = $ 0.13 / kWh
so the total cost
total_cost = energy unit_cost
total_cost = 15.6 0.13
total_cost = $ 2.028
rounding to two decimal places
total_cost = $ 2.03
