Projectile Motion Question 1: Calculating Time, Range, and Force in Golf Swing

[billybobay]

1. I think the most place I'm questioning my answer is the force part of it.

A golf club contacts a golf ball for 0.15 s at an angle to the horizontal and the ball subsequently strikes the ground a distance down the fairway. You choose an initial speed (between 25 m/s and 35 m/s) and the angle of projection (Between 15o and 22o) to calculate
the time between the ball leaving the club and when it first touches the ground,
the range of the ball down the fairway , and
the average force exerted by the club on the ball.
(assume the fairway is level horizontally. Mass of a golf ball is 0.046 kg)

Homework Equations

vh = 28.19 m/s cos 20 = vh/30
vv = 10.26 m/s sin 20 = vv/30
t = (0.0 m/s - 10.26 m/s) / -9.8
t = -10.26 / -9.8
t= 1.047 s

t= 2 (1.047)
t= 2.094 seconds for the ball to touch the ground

dx = (28.19 m/s) (2.094 s)
dx= 59.03 meteres

f=.046(-9.8)
f=-.45N

The Attempt at a Solution

Homework Statement
The ball will take 2.094 seconds to touch the ball 59.03 meteres down the fairway forced at -.45N.

 

[Delphi51]

vh = 28.19 m/s cos 20 = vh/30
vv = 10.26 m/s sin 20 = vv/30

Okay, looks like you chose the initial angle to be 20 degrees and the initial speed to be 30. Then your vh and vy are correct.
The time to touch down and range look good.

The F = ma = .046(-9.8) can't be right. The ball is not accelerating at 9.8 when hit by the club. Your are given that "club contacts a golf ball for 0.15 s". Perhaps you can find some way to calculate the force from that and its change in velocity.