Question

A rock was thrown horizontally from 100.0 m high cliff . It strikes the ground 90.0 from the base if the cliff. At what speed was it thrown. And a car weighing 12000 N parked on a 36 degree slope. Find the force tending to cause the car to roll down the hill. Find the acceleration of the car rolling down the hill.

Answer 1

The origin of the coordinate system can be defined as the starting point of the rock's motion. The equation that describes the horizontal motion of the rock is x = v_x * t. The equations that describe the vertical motion of the rock are y = v_0y * t + (1/2) * g * t^2 and v_y = v_0y + g * t.

Step-by-step explanation:

(a) The origin of the coordinate system can be defined as the starting point of the rock's motion. In this case, it would be the top of the cliff.

(b) The equation that describes the horizontal motion of the rock is:

x = vx * t

where x is the horizontal distance, vx is the horizontal velocity (which is constant as there is no horizontal acceleration), and t is the time.

(c) The equations that describe the vertical motion of the rock are:

y = v0y * t + (1/2) * g * t2

vy = v0y + g * t

where y is the vertical distance, v0y is the initial vertical velocity, g is the acceleration due to gravity (approximately -9.8 m/s²), and t is the time.

(d) The rock's velocity at the point of impact can be found using the vertical motion equation. At the point of impact, the rock's vertical distance will be equal to zero. Therefore, we can set y = 0 and solve for t. Once we have t, we can plug it into the equation for vy to find the rock's velocity at the point of impact.