3. A Truck is pulled by a rope horizontally. The mass of the truck is 200kg and the
tension in the rope is 500N. Assuming the initial velocity to be zero, how long
will it take the truck to reach a speed of 8m/s. Ignore the friction :
a) 2 second
b) 4.5 second
c) 3.2 second
d) 6.1 second. The answer is 3.2 but how ?
Good luck with your AGU entrance exam test this Saturday. :D
To solve this problem, we can use Newton's second law of motion, which states that the net force acting on an object is equal to the product of its mass and acceleration. In this case, we need to calculate the acceleration of the truck.
Step 1: Calculate the acceleration using Newton's second law:
Since we are given the mass of the truck (200 kg) and the tension in the rope (500 N), we can calculate the acceleration.
F = m * a
a = F / m
Plugging in the values:
a = 500 N / 200 kg
a = 2.5 m/s²
Step 2: Find the time it takes for the truck to reach a speed of 8 m/s.
We need to calculate the time it takes for the truck to accelerate from an initial velocity of 0 m/s to a final velocity of 8 m/s.
We can use the equation of motion:
v = u + at
where:
v = final velocity (8 m/s)
u = initial velocity (0 m/s)
a = acceleration (2.5 m/s²)
t = time
Plugging in the values:
8 m/s = 0 m/s + (2.5 m/s²) * t
Simplifying the equation:
8 m/s = 2.5 m/s² * t
t = 8 m/s / 2.5 m/s²
t = 3.2 s
Therefore, the correct answer is c) 3.2 seconds.