Auniform rectangular coil of total mass 270 g and dimensions 0.500 m * 1.00 m is oriented with its plane parallel to a uniform 4.00-t magnetic field (fig. e27.43). a current of 2.70 a is suddenly started in the coil. (a) about which axis (a1 or a2) will the coil begin to rotate? why? (b) find the initial angular acceleration of the coil just after the current is started.

If a rock is thrown upward on the planet mars with a velocity of 12 m/s, its height (in meters) after t seconds is given by h = 12t − 1.86t2. (a) find the velocity of the rock after two seconds. m/s (b) find the velocity of the rock when t = a. 12−3.72a m/s (c) when will the rock hit the surface? (round your answer to one decimal place.) t = s (d) with what velocity will the rock hit the surface? m/s