Question
I need all of these answered with the steps please.
A rifle with a weight of 30 N fires a 5.0-g bullet with a speed of 300 m/s. (a) Find the recoil speed of the rifle. (b) If a 700-N man holds the rifle firmly against his shoulder, find the recoil speed of the man and rifle. A 25.0-g object moving to the right at 20.0 cm/s overtakes and collides elastically with a 10.0-g object moving in the same direction at 15.0 cm/s. Find the velocity of each object after the collision. A 1200-kg car traveling initially with a speed of 25.0 m/s in an easterly direction crashes into the rear end of a 9000-kg truck moving in the same direction at 20.0 m/s. The velocity of the car right after the collision is 18.0 m/s to the east. (a) What is the velocity of the truck right after the collision? (b) How much mechanical energy is lost in the collision? Account for this loss of energy. The diameters of the main rotor and tail rotor of a single-engine helicopter are 7.60 m and 1.02 m, respectively. The respective rotational speeds are 450 rev/min and 4138 rev/min. Calculate the speeds of the tips of both rotors. Compare these speeds with the speed of sound. A sample of blood is placed in a centrifuge of radius 15.0 cm. The mass of a red blood cell is 3.0 10-16 kg, and the magnitude of the force acting on it as it settles out of the plasma is 4.0 10-11 N. At how many revolutions per second should the centrifuge be operated? Objects with masses of 200 kg and 500 kg are separated by a distance of 0.400 m. (a) Find the net gravitational force exerted by these objects on a 50.0-kg object placed midway between them. (b) At what position (other than infinitely remote ones) can the 50.0-kg object be placed so as to experience a net force of zero?
Explanation / Answer
a)30N are 3 kilos. 5 gr=0,005 kilos M1*U1=M2*U2 => 3*U1=0,005*300=>u1=0.5 m/s 700nt=70kilos 70+3=73 kilos (man+rifle) 73*u=0.005*300=> u= 0.02055