Sa steel ball with mass =5.21 g is moving horizontally with speed =412 m/s when it strikes a block of hardened steel with mass =14.8 kg (initially at rest). the ball bounces off the block in a perfectly elastic collision. (a) what is the speed of the block immediately after the collision?

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

Most of the volume of an atom is occupied by the

Which missing item would complete this alpha decay reaction ? > 228/88ra + 4/2he a.224/96 rn b. 232/90 th c. 230/92 u d. 235/92 u