Answer:
a) Yes because spiderman isn’t part of the system (the train), so he exerts an external force on the system, causing it to slow. The sign is negative because the train is slowing negative.
b) The train was initially moving, so it had kinetic energy, the energy of movement. There isn’t the same amount anymore because spiderman did work onto the train. Work is defined by the change of kinetic energy of the system, so the train didn’t have the same amount of that type of energy at the end.
I hope this helps! :)
Answer:
0.915 Nm
Explanation:
1 revolution = 2π rad
We can use the following equation of motion to find out the acceleration acting on the disk
where ![\omega v = 2.5 rad/s is the final angular velocity of the disk, [tex]\omega_0](https://tex.z-dn.net/?f=%5Comega%20v%20%3D%202.5%20rad%2Fs%20is%20the%20final%20angular%20velocity%20of%20the%20disk%2C%20%5Btex%5D%5Comega_0)
= 0 rad/s is the initial velocity of the can when it starts from rest, 
is the angular distance traveled, 
is the angular acceleration of the disk, which we care looking for:
The moment of inertia of the solid disk is:
where m is the mass and R is the radius of the disk
The net torque applied is
Answer:
320 N/m
Explanation:
F = k·Δx
where
F is the restoring force of the spring
k is the proportionality constant called the ‘spring constant’
Δx is the change in the spring’s position due to the deformation.
You need the k so
25 cm= 0.25m
k=F/∆x = 80/0.25 = 320 N/m
Answer:
40hz has less frequency of sound and 300hz has more frequency of sound which means 40hz has less crest and troughs , so it has less reachability thank 300hz.
Explanation:
the answer is c in question 7
