During a collision with another car, the occupants of a minivan initially travelling at 4.0 m/s come to a complete stop in 0.5 s. What was the acceleration of the occupants of the minivan? a) 8.0 m/s2

b) –8.0 m/s2

c) 2.0 m/s2

d) –2.0 m/s2

b) - 8.0

Explanation: Acceleration is a vector indicating a rate an object's velocity changes over time:

a =

and its SI unit is

For the minivan to stop, it takes a period of 0.5s:

a =

a = 8.0

As a vector, acceleration has magnitude (8) and direction. Since it is stopping, the minivan has a direction opposite to the other car, which means acceleration is negative. So: a = .

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.

iron would move it is magnetic there is a mag field around the current in the wire