Matt has a portable basketball goal in his driveway. He has the basket set 8 ft
ID: 2118651 • Letter: M
Question
Matt has a portable basketball goal in his driveway. He has the basket set 8 ft (2.4 m) high so he
can practice dunking the ball. He slams the ball through the hoop and then hangs onto the rim.
This exerts a downward force of 600 N on the front of the rim. The front of the rim is 1.1 m in
front of the front edge of the portable basketball goal%u2019s base. The mass of the whole portable
basketball goal is 70 kg. The center of gravity of the portable basketball goal is 1.0 m behind
the front edge of its base.
a. How much torque is produced around the front of the goal base by the 600 N force Matt
exerts on the front of the rim?
ANSWER: 660 Nm tipping torquw
b. How much torque would be needed to tip the goal? ANSWER:greater than 687 Nm
c. What is the largest vertical force that can be exerted on the front edge of the rim before the
portable basketball goal begins to tip? ANSWER: 625 N
Answers provided, please provide workout steps
Explanation / Answer
Force exerted by matt [F] = 600 N
distance from the front edge [r ] = 1.1m (in front)
Torque = F*r =600*1.1 Nm = 660 Nm [ANS]
b) mass of the goal post [m] = 70kg
force due to the mass = m*g = 70*9.8 N = 687 N
distance of the center of mass from the front edge [r ] = 1m (in back)
Torque required = F*r =687*1 Nm = 687 Nm [ANS]
c) Let the force exerted on the front edge be -> x
distance from the front edge [r ] = 1.1m (in front)
Torque = F*r
687 Nm = x* 1.1 m
x = 625 N [ANS]