Question

co200.000 10.5 A block of mass 0.5 kg on a horizontal surface is attached to a horizontal spring of negligible mass and spring constant 50 N/m. The other end of the spring is attached to a wall, and there is negligible friction between the block and the horizontal surface. When the spring is unstretched, the block is located at x = Om. The block is then pulled to x = 0.3m and released from rest so that the block-spring system oscillates between x = -0.3 m and x = 0.3 m. What is the magnitude of the acceleration of the block and the direction of the net force exerted on the block when it is located atx 0.3m? O Magnitude of Direction of Acceleration Net Force 30 m/s2 Positive o Magnitude of Direction of Acceleration Net Force 30m/s2 Negative O Magnitude of Direction of Acceleration Net Force O m/s2 Positive Magnitude of Direction of Acceleratic Net Force O m/s2 Negative

Answer 1

Amplitude A= 0.3 m

Angular frequency

$\omega = ( k/m)^{1/2}$

At x= 0.3 m i, e at the right end magnitude of acceleration is

$a= \omega ^2 A = ( k/m) A$

# Direction of net force at that point is towards mean position x =0 m , means toward negative X , ( -X ) direction.