Question

A force of 1.50 N acts on a 0.20 kg trolley so as to accelerate it along an air track. [04 Marks]

The track and force are horizontal and in line. How fast is the trolley going after acceleration from rest through 30 cm, if friction is negligible?

Answer 1

Vf = 2.12 [m/s]

Step-by-step explanation:

To solve this problem we must first find acceleration using Newton's second law, using mass and force.

ΣF = m*a

where:

F = force = 1.5 [N]

m = mass = 0.2 [kg]

a = acceleration [m/s²]

Now clearing a, we have:

`a = F/m\\a = 1.5/0.2\\a = 7.5 [m/s^(2)]`

Now we must use the following expression of kinematics, to find the final speed, we must take into account that the initial speed is equal to zero, since the car starts from zero.

`v_(f)^(2) =v_(o) ^(2) +2*a*x\\v_(f) ^(2) = 0 + (2*7.5*0.3)\\v_(f) = √(4.5)\\v_(f) = 2.12 [m/s]`