QuestionIn the figure, an airport luggage carrying train with a tractor (T) is pulling three luggage carts, , , and , with constant velocity of m/s. If kg, kg, kg, and kg (there is no friction), then the force in the connection between the tractor (T) and cart is:
Studdy Solution
STEP 1
What is this asking?
How strong is the pull between the tractor and the first cart if the whole train is moving at a steady speed?
Watch out!
Don't get tricked by all the numbers!
Constant velocity means *zero* acceleration.
STEP 2
1. Visualize the forces
2. Calculate the total mass being pulled
3. Find the force
STEP 3
Imagine the train moving at a constant speed.
That means the tractor is pulling just hard enough to keep everything moving at m/s.
No speeding up, no slowing down!
STEP 4
The tractor (T) is pulling *all* the carts (, , and ).
The force between T and is what's keeping those carts moving.
STEP 5
The tractor is pulling , , and .
Let's add those masses together to find the **total mass** being pulled by the tractor.
STEP 6
So, the tractor is pulling a total of **65 kg** of carts!
STEP 7
Since the train is moving at a *constant* velocity, the **net force** is *zero*!
This means the force the tractor exerts is perfectly balanced by other forces (in this case, there are no other forces since we're told there's no friction).
Newton's second law tells us: .
STEP 8
Since the velocity is constant, the acceleration () is **zero**.
STEP 9
The **net force** acting on the *entire* train is zero, but we're looking for the force *between* the tractor (T) and the first cart ().
This force is what's pulling the carts , , and .
STEP 10
Since the net force on the three carts is also zero, the force between the tractor and must be zero.
STEP 11
The force in the connection between the tractor (T) and cart is .
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