A 10 kg mass on a horizontal friction free air track is accelerated by a string attached to another 10-kg mass hanging vertically from a pulley as shown.What is the force due to gravity in newtons of the hanging 10-kg mass? What is the acceleration of the system of both masses?
1 ) The force due to gravity:
F g = m g = 10 kg 9.81 m/s²
F g = 98.1 N
2 ) The system:
m 1 a = m g - T
+
m 2 a = T
-----------------------
a (m 1 + m 2) = m g
a * 20 kg = 98.1 N
a = 98.1 : 20
a = 4.905 m/s²
1. Answer;
Force = 98.1 Newtons
Explanation;
-On the hanging mass the net force is
Fnet = Mhg - T = Mha where Mh is the mass = 10kg, g = 9.81m/s², and T the tension in the string. Its acceleration is a ( same as g)
Thus; Force = 10 kg × 9.81 m/s²
= 98.1 Newtons.
2. Answer;
a = 4.905 m/s²
Solution;
-We know that that T = Msa, but Fnet = Mhg - T = Mha
Substituting; T with Msa
Mhg - Msa = Mha
Mha + Msa = Mhg
a = Mhg/(Mh + Ms)
= 10.0kg9.81 m/s²/(10kg + 10kg)
= 4.905 m/s²