1 A boy's catapult is made of rubber cord
which is 42 cm long, with 6 mm diameter
of cross-section and of negligible mass. The
boy keeps a stone weighing 0.02 kg on it
and stretches the cord by 20 cm by applying
a constant force. When released, the stone
flies off with a velocity of 20 ms -1 Neglect
the change in the area of cross-section of
the cord while stretched. The Young's
modulus of rubber is closest to:​

10 newton object is placed 3 meters from the fulcrum. at what distance on the other side would you need to place a 15 newton object to balance the lever? show your work!

What pressure difference is required between the ends of a 2.0-m-long, 1.0-mm-diameter horizontal tube for 40 c water to flow through it at an average speed of 4.0 m/s?

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants