A car has a mass of 710 kg. It starts from rest and travels 40.0 m in 3.0s. The car is uniformly accelerated during the entire time. How big is the net force acting on the car?

Question

35040 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-12-04T19:57:33

#6300 "N"#

We will employ the following equation of kinematics

#x = 1/2at^2#

which describes an object traveling in one dimension with a constant acceleration and an initial velocity of zero.

We know the displacement and the time elapsed so we may solve for the acceleration:

#40.0 "m" = 1/2a(3.0"s")^2#

Solving for #a# yields:

#a = 8.89 "m"/"s"^2#

Now, knowing the acceleration of the car as well as the mass of the car we can apply Newton's second law, which states

#F_("net") = ma#

All we need to do is plug in our values for #m# and #a#:

#F_("net") = 710"kg"*8.89 "m"/"s"^2 = 6311.9 "N"#

Considering the fact that our final answer should have only two significant digits, we will round to the nearest hundred:

#F_("net") = 6300 "N"#