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Physics Time for truck to go down ramp and reach point B

Porter Tawa

New member
Apr 2, 2019
2
A 2000 kg truck is resting at the top of a parking lot ramp which is at a 15 degree slope. It is then shifted into Neutral and starts moving.
How long does it take the truck to get from A to B in seconds?

There is a 15 degree slope on the ramp.
uk is 0.08
Assume there is no air resistance.
 

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Porter Tawa

New member
Apr 2, 2019
2
Thank you for your reply.
I took a look at the link. It requires a paid membership and it does not discus the time it takes to get from point A to B.
 
Last edited:

skeeter

Well-known member
MHB Math Helper
Mar 1, 2012
702


A 2000 kg truck is resting at the top of a parking lot ramp which is at a 15 degree slope. It is then shifted into Neutral and starts moving.
How long does it take the truck to get from A to B in seconds?

There is a 15 degree slope on the ramp.
uk is 0.08
Assume there is no air resistance.
You have accelerated motion from A down the ramp, then constant speed from the bottom of the ramp to B.

To determine acceleration down the ramp, note Newton's 2nd law ...
$F_{net} = ma = mg\sin{\theta} - f_k$

The kinematics equation for constant acceleration down the ramp would be $\Delta x = v_0 \cdot t - \dfrac{1}{2}at^2$
You're given the displacement down the ramp and you are also told the truck starts from rest. If you have calculated the magnitude of acceleration from the force equation above, then you should be able to determine the time required from point A to the ramp bottom.

To determine the time on the horizontal surface from the ramp bottom to B, you'll need to calculate the truck's speed at the ramp bottom. There are a couple of ways to calculate that speed value from other kinematics equations for constant acceleration.