How long did the train accelerate if his final speed is 72km/h and his acceleration is 0.5 m/s2

When a 5.0kg cart undergoes a 2.2m/s increase in speed, what is the impulse of the cart

In an experiment, how can i change human errors? be specific.

During the experiment if you could triple the breakaway magnetic force with all other quantities left unchanged, what is the new value for the critical velocity if it was v0 (initial velocity), initially? (b) now if you halved the radius with all other quantities left unchanged, what is the new critical velocity if it was v0 (initial velocity), initially? (c) if during the experiment, critical velocity quadrupled with all other quantities left unchanged, what is the new breakaway force if its magnitude was initially f0,?