Question

A semi-trailer is coasting downhill along a mountain highway when its brakes fail. The driver pulls onto a runaway truck ramp that is inclined at an angle of 17.0° above the horizontal. The semi-trailer coasts to a stop after traveling 120 m along the ramp. What was the truck's initial speed? Neglect air resistance and friction.

Answer 1

26.2 m/s

Step-by-step explanation:

We are given that

`\theta=17^(\circ)`

Distance traveled by truck =s=120 m

Final speed of truck =v=0

We have to find the initial speed of truck.

`v^2-u^2=2gs sin\theta`

Where g=
`-9.8 m/s^2`

Substitute the values

`0-(u)^2=2(-9.8)(120)sin17`

`-u^2=-686.784`

`u^2=686.784`

`u=√(686.784)`

u=26.2 m/s

Hence, the initial velocity of truck=26.2 m/s