- #1
13physicsdude
- 10
- 0
HELPHow is this possible?!? The hanging mass is lighter then the cart!
The cart in Figure 4 has a mass of 2.3 kg and is attached to a 1.7 kg object. Calculate the acceleration of the cart given the following assumptions.
A) The force of friction is negligible
B) The frictional force acting on the wheels of the cart has a magnitude of 0.6 N.
C) Explain why the hanging mass does not accelerate downward at 9.8 m/s2
**btw Figure 4 simply shows a cart with wheels sitting on a horizontal surface with a string attached to the front, running from the front of the cart through a single pulley system at the corner of the table with a hanging mass attached to the end of the string, hanging off the table.
A)
m1:
Fnet=T
ma=T
T=2.3a
m2:
Fg=mg
mg-t=ma
(1.7)(9.8)-T=1.7a
m1+m2:
16.66-2.3a=1.7a
16.66=4a
∴ a=4.165 m/s2
B)
m1:
T-Ff=ma
T-0.6=2.3a
m2:
Fg-t=ma
1.7g-t=1.7a
m1+m2:
1.7g-0.6=4a
16.66-0.6=4a
a=16.66-0.6/4
a=4.015 m/s2
C)
The reason the hanging mass does not accelerate downwards at 9.8 m/s2 is simply because gravity is not the only force acting on the hanging object. Tension of the rope is also a force acting on the object and is counteracting the effect of gravity just not at the same magnitude, that's why it still accelerates downward just not at 9.8 m/s2
Homework Statement
The cart in Figure 4 has a mass of 2.3 kg and is attached to a 1.7 kg object. Calculate the acceleration of the cart given the following assumptions.
A) The force of friction is negligible
B) The frictional force acting on the wheels of the cart has a magnitude of 0.6 N.
C) Explain why the hanging mass does not accelerate downward at 9.8 m/s2
**btw Figure 4 simply shows a cart with wheels sitting on a horizontal surface with a string attached to the front, running from the front of the cart through a single pulley system at the corner of the table with a hanging mass attached to the end of the string, hanging off the table.
The Attempt at a Solution
A)
m1:
Fnet=T
ma=T
T=2.3a
m2:
Fg=mg
mg-t=ma
(1.7)(9.8)-T=1.7a
m1+m2:
16.66-2.3a=1.7a
16.66=4a
∴ a=4.165 m/s2
B)
m1:
T-Ff=ma
T-0.6=2.3a
m2:
Fg-t=ma
1.7g-t=1.7a
m1+m2:
1.7g-0.6=4a
16.66-0.6=4a
a=16.66-0.6/4
a=4.015 m/s2
C)
The reason the hanging mass does not accelerate downwards at 9.8 m/s2 is simply because gravity is not the only force acting on the hanging object. Tension of the rope is also a force acting on the object and is counteracting the effect of gravity just not at the same magnitude, that's why it still accelerates downward just not at 9.8 m/s2