At a certain time a particle had a speed of 43 m/s in the positive x direction, and 5.8 s later its speed was 95 m/s in the opposite direction. What was the average acceleration of the particle during this 5.8 s interval?

Explanation:

Average acceleration is defined as the change on velocity on an interval of time:

with Vf the final velocity, Vi the initial velocity and t the time interval. Note that the initial velocity is positive because is in the positive x direction and final velocity is negative because is in the opposite direction, so:

The negative sign indicates that the acceleration is in the negative x direction.

the first american roller coaster was the mauch chunk switchback railway, built in the mountains of pennsylvania in the mid-1800s. the track, originally built to send coal to a railway, was reconfigured as a "scenic tour."

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg