a sled was pushed up a 25 degree incline reaching a max vertical height 1.35m .. what was its initial speed?

Question

a sled was pushed up a 25 degree inclined plane reaching a max vertical height 1.35m higher than it was when it first started .. what was its initial speed?

HELP PLEASE!

Answer 1

If the sled was "pushed up" the incline, than its initial speed would likely have been 0 - it was probably just sitting there before someone or something started to push it. If you have the question right, than that's about the best answer anyone can give.

However, if the sled was pushed earlier, gained some speed and then on its own momentum, climbed up the incline, than we can calculate its initial speed. In that case, the angle of the incline is extraneous information if we assume that the incline itself is smooth and frictionless. It's only the height that matters.

To solve, just remember that all of the kinetic energy that the sled had as it started up the incline is converted to potential energy at the top of its climb.

The potential energy at the top of the incline is:
Ep = mass x height x force of gravity
Ep = mass x 1.35 x 9.81
Ep = mass x 13.24

The kinetic energy at the bottom of the incline is:
Ek = 1/2 x mass x speed^2

We know that Ep=Ek, so
1/2 x mass x speed^2 = 13.24 x mass

Eliminating mass from both sides:
1/2 x speed^2 = 13.24

Multiplying both sides by 2:
speed^2 = 26.48
speed = square root of 26.48
speed = 5.15 m/s

The sled was traveling at a little over 5 metres per second.

Answer 2

Initially, it wasn't moving, so Zero. (The instant you stop pushing the sled it is neither moving up or down the incline) Then it will start down the slope.
You need a bit more information to persue this question. like the coefficient of friction, the mass of the sled etc.

Answer 3

once you're asserting that its 0..... then lemme enable you comprehend, its incorrect... it incredibly is truthfully under the preliminary velocity.... provided that a ball is hit up interior the air (vertically up), then does the cost turns into 0 on the max height Cheers!

Answer 4

gravitational potential energy = kinetic energy
mgh=1/2mv^2

masses cancel out and h=1.35sin(25)

9.8(1.35sin25)=1/2v^2

simply solve for v