If you cannot get a chair to move across the floor, it is because static friction opposes your push. When you say static or kinetic friction the two object that facing each other are opposing each other. That's why you're having a hard time pushing the chair.

7 0

3 years ago

A stuntwoman is going to attempt a jump across a canyon that is 77 m wide. The ramp on the far side of the canyon is 25 m lower

charle [14.2K]

Answer:

She will make the jump.

Explanation:

We have equation of motion , $s= ut+\frac{1}{2} at^2$ , s is the displacement, u is the initial velocity, a is the acceleration and t is the time.

First we will consider horizontal motion of stunt women

Displacement = 77 m, Initial velocity = 28 cos 15 = 27.05 m/s, acceleration = 0

Substituting

$77= 27.05t+\frac{1}{2} *0*t^2\\ \\ t=77/27.05=2.85 seconds$

So she will cover 77 m in 2.85 seconds

Now considering vertical motion, up direction as positive

Initial velocity = 28 sin 15 = 7.25 m/s, acceleration =acceleration due to gravity = -9.8 $m/s^2$ , time = 2.85

Substituting

$s=7.25*2.85-\frac{1}{2}*9.8*2.85^2=20.69-39.80 =-10.11 m$

So at time 2.85 stunt women is 10.11 m below from starting position, far side is 25 m lower. So she will be at higher position.

So she will make the jump.

6 0

3 years ago

Newton's First Law says that an object at rest will stay at rest, and an object in motion will stay in motion unless:

Verdich [7]

Answer: Acted on by equal forces in opposite direction

Explanation:

Newton's First Law says that every body continue in its state of rest or constant speed on a straight line unless being acted upon by an external force.

6 0

3 years ago