Urgent ! -
answer asap!

1. what is the mass of a car that weighs 140,000 n?

2. calculate dave's acceleration knowing that in a race he starts from rest and reaches a speed of 15.3m/s in 4.71 s.

3. determine the speed of the block of wood when a 12 g bullet hits a 2.3 kg block at a speed of 350 m/s.

4. a 22 kg astronaut in orbit pushes a 40kg astronaut. if the 22kg astronaut travels away at 10 m/s what speeds and direction will the 40 kg astronaut travel away at.

Try this option, the answers are marked with colour.

not really sure but thinking 1.54 mm/us

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