7. A small block carrying a charge of +7.20 C and a mass of 60.0 grams is initially placed At point A, which is just inside the lip of frictionless and nonconducting hemispherical bowl whose radius is 10 cm. There are two electric fields acting on the block: One is a uniform field that points to the left, and the other from a - 0.500 nC point charge. The block is released from rest at point and slides along the inner surface of the bowl. When the block has reached Point B its speed is 0.900 m/s. What must be the size of the uniform electric field? A Euniform = ? -0.500 nC B } 4 cm