In a football game, a receiver is standing still, having just caught a pass. before he can move, a tackler, running at a velocity of +4.1 m/s, grabs him. the tackler holds onto the receiver, and the two move off together with a velocity of 2.1m/s. the mass of the tackler is 105 kg. assuming that the momentum is conserved, find the mass of the receiver. what is the average force on the receiver if in contact for 1 second? what is the average force on the tackler if in contact for 1 second?

The heater element of a 120 v toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. the resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 ω·m. the toaster is operated at a voltage of 120 v. (a) what is the power drawn by the toaster? (b) if the cost of electricity is 12 ¢ per kilowatt-hour, and it takes 2 minutes to toast bread, how much does it cost for toasted bread? (c) when the heater element is at room temperature, is the resistivity in the nichrome wire greater than, less than, or equal to it’s resistivity when at operating temperature? explain.