D. Copper and Gold
Copper and gold are used a lot in electrical applications.
Air and wood are insulators and glass is also kinda bad...
We have: A= F.s
So, A = 22 x 16
A= 352J
Só A is correct answer
Answer:
(a) The spring constant is 426N/m
(b) The mass is 5.65kg
Explanation:
(a) Energy stored in the spring (E) = 3.6J, extension (e) = 0.13m
E = 1/2Ke^2
3.6 = 1/2 × K × 0.13^2
K (spring constant) = 3.6×2/0.0169 = 426N/m
(b) F = Ke = 426 × 0.13 = 55.38N
Assuming the maximum acceleration (a) is 9.8m/s^2
Mass (m) = F/a = 55.38/9.8 = 5.65kg
Answer: 1960 N
Explanation:
The bear is sliding down at constant velocity: this means that its acceleration is zero, so the net force is also zero, according to Newton's second law:

There are two forces acting on the bear: its weight W, pulling downward, and the frictional force Ff, pulling upward. Therefore, the net force is given by the difference between the two forces:

From the previous equation, we find that the frictional force is equal to the weight of the bear:
