Find Time in Physics: Ramp, Piano & Moving Van

[karasis]

A piano has been pushed to the top of the ramp at the back of a moving van. The workers think it is safe, but as they walk away, it begins to roll down the ramp.If the back of the truck is 1.4 m above the ground and the ramp is inclined at 20 degress, how much time do the workers have to get to the piano before it reaches the bottom of the ramp?

i have know idea how to set this problem up

 

[kmikias]

Draw freedody diagram and every thing will be clear

 

[baba89]

I can help you solve this problem using principles of physics. First, we need to determine the initial velocity of the piano as it starts rolling down the ramp. This can be calculated using the formula: v = u + at, where v is the final velocity, u is the initial velocity (which is 0 in this case), a is the acceleration, and t is time. We can also use the formula a = gsinθ, where g is the acceleration due to gravity (9.8 m/s^2) and θ is the angle of inclination (20 degrees). Plugging in the values, we get a = 9.8 m/s^2 x sin 20 degrees = 3.36 m/s^2. Now, we can solve for the initial velocity using the first formula: v = 0 + 3.36 m/s^2 x t. Since the piano is starting from rest, we can ignore the initial velocity term and solve for t: t = v/a = 0.42 seconds. This means that the workers have approximately 0.42 seconds to get to the piano before it reaches the bottom of the ramp. It is important to note that this calculation assumes ideal conditions and does not account for factors such as friction or air resistance, which may affect the actual time. Therefore, it is important for the workers to act quickly and safely to retrieve the piano before it reaches the bottom of the ramp.