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 Homework Statement

A perfect hemisphere of frictionless ice has radius R=7 meters. Sitting on the top of the ice, motionless, is a box of mass m=7 kg.
The box starts to slide to the right, down the sloping surface of the ice. After it has moved by an angle 11 degrees from the top, how much work has gravity done on the box?
How fast is the box moving?
At some point, as the box slips down the ice and speeds up, it loses contact with the ice and flies off into the air. At what angle from the top does the box leave the ice? I'll provide the units for you.
(Hint: At the critical point, the component of the gravitational force pointing toward the center of the hemisphere is exactly equal to the force required to keep the box moving in a circular path around the center of the hemisphere)
 Homework Equations
 KE=(1/2)mv^2
Homework Statement: A perfect hemisphere of frictionless ice has radius R=7 meters. Sitting on the top of the ice, motionless, is a box of mass m=7 kg.
The box starts to slide to the right, down the sloping surface of the ice. After it has moved by an angle 11 degrees from the top, how much work has gravity done on the box?
How fast is the box moving?
At some point, as the box slips down the ice and speeds up, it loses contact with the ice and flies off into the air. At what angle from the top does the box leave the ice? I'll provide the units for you.
(Hint: At the critical point, the component of the gravitational force pointing toward the center of the hemisphere is exactly equal to the force required to keep the box moving in a circular path around the center of the hemisphere)
Homework Equations: KE=(1/2)mv^2
The work of gravity on the box across= mg(distance) = mg(radiusradius(cos(theta)))
Thus work of gravity= (7kg)(9.8m/s^2)(77cos(11))= 8.8J
velocity = (2(8.8J)/(7kg))^(1/2)=1.59m/s
I am stuck on how to find the angle when the box slips
The box starts to slide to the right, down the sloping surface of the ice. After it has moved by an angle 11 degrees from the top, how much work has gravity done on the box?
How fast is the box moving?
At some point, as the box slips down the ice and speeds up, it loses contact with the ice and flies off into the air. At what angle from the top does the box leave the ice? I'll provide the units for you.
(Hint: At the critical point, the component of the gravitational force pointing toward the center of the hemisphere is exactly equal to the force required to keep the box moving in a circular path around the center of the hemisphere)
Homework Equations: KE=(1/2)mv^2
The work of gravity on the box across= mg(distance) = mg(radiusradius(cos(theta)))
Thus work of gravity= (7kg)(9.8m/s^2)(77cos(11))= 8.8J
velocity = (2(8.8J)/(7kg))^(1/2)=1.59m/s
I am stuck on how to find the angle when the box slips
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