PHYSICS HELPPPPPPPPPPPPPPPPPPP?

Question

A car mass (M) runs off the edge of a table with a constant speed (Vo) that is (H) high. The acceleration of gravity is (g). Determine how far the car lands from the base of the table (D) in terms of Vo, H and g ????

CHALLENGE, if the car continue to run WITHOUT FRICTION from the base of the table, determine the resulting velocity of the car.

Answer 1

the key physics here is that the car will maintain its horizontal speed throughout the trip in air since there are no horizontal forces acting on the car

the time the car is in the air before it hits the ground is given by:

H=1/2 g t^2 so we have that

t=sqrt[2H/g]

the distance the car travels horizontally is just this time multiplied by its horizontal speed, so that we have:

D=v0 x sqrt[2H/g]

to find the velocity after impact, you would need to know something about the nature of the impact...you would need to know the time it takes for the ground to exert its force on the car...

remember, the car has both a horizontal and vertical component of motion when it hits the floor...this means the floor will exert a force on the car when it hits..you will need to know a lot about the nature of the interaction to actually predict a velocity...

however, my guess is that your teacher wants you to calculate the total speed of the car when it hits the ground, the car has horizontal speed that you just calculated and a vertical speed given by gt or

g sqrt[2H/g]

the total speed at impact is sqrt[vhor^2+vvert^2]=

sqrt[2 vo^2 H/g + 2Hg]

my guess is your teacher wants you to say that none of this energy will be lost in the collision and that the car will continue forward with this speed

Answer 2

The car will fall for:

h = ½gt²

t = √2h/g

D = Vo t

D = Vo √2h/g

I guess I'm dumb, because I'm not sure how to determine the loss of KE on impact.