1.
a poorly tuned yugo can accelerate from rest to a speed of 28 m/s in
20 s.
a) what is the average acceleration of the car?
b) what distance does it travel in this time?

Explanation:

Average acceleration is defined as the rate of change of velocity to the rate of change of period. Change of velocity refers to the difference between final velocity and initial velocity. The unit of acceleration is meter/sec/sec (or)   m s^2.

Avg Acceleration=(Final velocity - Initial velocity) /(Final time - Initial time)

a. To find the average acceleration of the car, (initial velocity and initial time   is 0, the final velocity is 28 m/s, final time = 20 s)

               Avg acceleration of the car = (28 - 0) / (20 - 0)

                                                              = 28 / 20 = 1.4 m / s^2.

b. The distance traveled is given by the product of speed and time

     Distance traveled = Speed * Time

      The Distance traveled by the car = 28 * 20 = 560 m.

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