A block of mass 0.5 kg is pushed against a horizontal spring until the spring is compressed a distance x = 0.4 m. The spring constant is 450 N/m. When it is released the block travels along a horizontal frictionless surface then reaches a vertical circular track of radius R = 2.9 m and continues to move up the track. The block experiences friction while sliding up the track. The block reaches the top of the track with a speed of 4.1 m/s. Find the change in mechanical energy caused by friction (in J).

answer: a. same unit

explanation:

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me

can u provide the graph and if its not possible

then i can tell u the segment where the

average time interval starts degrading is the segment where the car is slowing down

it is b. absorbs thermal energy