physics help por favor?
Janet jumps off a high diving platform with
a horizontal velocity of 1.51 m/s and lands in
the water 1.1 s later.
The acceleration of gravity is 9.8 m/s2 .
a) How high is the platform?
Answer in units of m.
b) How far from the base of the platform does
she land?
Answer in units of m.
Comments
a) t = sqrt(2s/g)
1.1 = sqrt(2s/9.8)
height = 5.93 m
b) x = v*t
x = (1.51 m/s)*(1.1s)
x = 1.66 m
To The Correct Answer: Think about what you are saying. By having acceleration in your x component of motion, you are saying the diver is being accelerated in the x direction. Gravity does not act in the x direction. And, yes, I do know that x and y components are independent of each other. That's how I know there is no acceleration in the x direction.
a) If she jumps off with a velocity of 1.51 m/s and lands 1.1 seconds later, then since distance = speed/time, then the distance eshe must have fallen is 1.51 seconds / 1.1 m/s = 1.37 meters.
b) x = 1/2 (at^2) so
x = 1/2(9.8 * 1.51^2)
x = 11.2 meters.
Obviously, SYN doesn't know what he is talking about because he doesn't know that horizontal and vertical motions are independent.