Answer:
A= 150 J
Explanation:
Kinetic energy is the energy of an object in motion.
The formula for kinetic energy is ;
K.E = 1/2 * m *v² where m is mass and v is velocity
Work done is equal to change in kinetic energy
W= Δ K.E
Given that K.E = 150 J
Taking that the ball was stationary before it was thrown, this makes its initial kinetic energy to be 0 J so the work done will be
W= Δ K.E
W= 150 - 0
W= 150 J
Answer:
Coefficient of kinetic friction = 0.146
Explanation:
Given:
Mass of sled (m) = 18 kg
Horizontal force (F) = 30 N
FInal speed (v) = 2 m/s
Distance (s) = 8.5 m
Find:
Coefficient of kinetic friction.
Computation:
Initial speed (u) = 0 m/s
v² - u² = 2as
2(8.5)a = 2² - 0²
a = 0.2352 m/s²
Nweton's law of :
F (net) = ma
30N - μf = 18 (0.2352)
30 - 4.2336 = μ(mg)
25.7664 = μ(18)(9.8)
μ = 0.146
Coefficient of kinetic friction = 0.146
Answer:
The car slowing from 60 m/s to 0 m/s
Explanation:
The bird flying at 10m/s for 10 seconds will have the same speed for those 10 seconds. So we can say it doesn't have a varying speed (During those 10 seconds, we don't have any information about what happens later).
The fish moving at 2m/s for 5 minutes will have the same speed for those 5 minutes. So we can say it doesn't have a varying speed (During those 5 minutes, we don't have any information about what happens later).
The car traveling the speed limit, we know that his speed is the speed limit. It doesn't change.
The car slowing from 60 m/s to 0 m/s needs to change his speed in order to go from 60 m/s to 0 m/s. The speed will decrease progressively until the car completely stops.
Based on the description, it will be most likely that he believes in Oscillating model (also known as Cyclic model) of the universe
Based on this model, the gravitational force will prevent further expansion by pulling back the matters and undergo a bounce
hope this helps
