Question

a ball with mass of 8.00kg...

2. A ball with mass of 8.00 kg is thrown downward with a speed of 15.0 m/s. When it has dropped 10.0 m, its speed is 18.0 m/s. While falling, the ball has an upward, constant drag force of unknown magnitude D. What is D? Ans: 38.9 N 3. A 2.00 kg object is attached to a Hooke's Law spring with k = 250 N/m. When the spring is compressed by 16.0 cm, the object has a speed of 1.30 m/s. The spring eventually makes the object turn around. How much is the spring compressed when the object turns around? What is the maximum stretch in the spring? The motion is on a horizontal, frictionless surface. Ans: 0.198 m for both 4. An object with mass m is attached to a Hook's Law spring with constant k. When the spring is compressed by a distance d, the object has a speed of v. The spring eventually makes the object turn around. How much is the spring compressed when the object turns around? What is the maximum stretch in the spring? The motion is on a horizontal, frictionless surface. Ans: x= negative solution for compression, positive solution for max stretch

Answer 1

Ans:

Using third kinematical equation,

نه - 2

Putting all the values,

182 – 152 2 x 10 mg-F m

Here , F is the constant force,

78.4 - F 3 x 33 2 x 10

78.4 - F = 39.6

F = 38.8 N