Problema Solution
A constant horizontal force of 30 N acts on a cartthat sits on a frictionless horizontal plane. The cart starts fromrest and is observed to move 100 meter in 5.0 sec.
a) What is the mass of the cart?
b) If the force ceases to acts at the end of 5.0 sec.How far will the cart moce in the next 10 sec?
Answer provided by our tutors
F=30 N
a is the acceleration of the car
m is the mass of the car
v is the velocity of the car after 5 s
Δt=5 s
s=100 m
s2 is the answer to b)
Δt2
(1) s=aΔt2/2
(2) F=ma
(3) v=aΔt
from (1) we got a=2s/Δt2
from (2) we got a=F/m
so 2s/Δt2=F/m therefore m=FΔt2/(2s) so m=3.75 kg
from (3) and from a=2s/Δt2 we got v=2s/Δt
s2=s+vΔt2=s+2sΔt2/Δt
so s2=500 m