A substance made up of only one type of element
Answer: Because new theories can come out that better explain observations and experimental results can replace old theories.
Explanation: Theories more than ten years old are usually out of date. Scientists want to prove that the work of other scientists is wrong. New evidence that supports a change prompts scientists to modify earlier theories.
Answer:
0.0675 seconds
Explanation:
From the question,
We apply newton's second law of motion
F = m(v-u)/t.................... Equation 1
Where F = force exert by the brake, v = final speed, u = initial speed m = mass of the bicycle, t = time.
make t the subject of the equation
t = m(v-u)/F................... Equation 2
Given: m = 180 kg, u = 6.0 m/s, v = 0 m/s (comes to stop), F = -1600 N ( agianst the dirction of motion)
Substitute these value into equation 2
t = 180(0-6.0)/-1600
t = -1080/-1600
t = 0.0675 seconds.
Answer:
Explanation:
spring constant k = 425 N/m
a ) At the point of equilibrium
restoring force = frictional force
= kx = 10 N
425 x = 10
x = 2.35 cm
b )
Work done by frictional force
= -10 x 2.35 x 10⁻² x 2 J ( Distance is twice of 2.35 cm )
= - 0.47 J
= Kinetic energy remaining with the cookie as it slides back through the position where the spring is unstretched .
= 425 - 0.47
= 424.53 J
=
