میکانیات

A ball is thrown vertically upward at 20 m/s. What maximum height does it reach? (g = 10 m/s2, no air resistance)

• 1 10 m
• 2 20 m
• 3 40 m
• 4 5 m

A ball is thrown vertically upward at 20 m/s. How long does it take to reach its highest point? (g = 10 m/s2, no air resistance)

• 1 1 s
• 2 4 s
• 3 2 s
• 4 0.5 s

A 5 kg block slides down a frictionless incline of 30 degrees. What is its acceleration? (g = 10 m/s2)

• 1 5 m/s2
• 2 10 m/s2
• 3 8.7 m/s2
• 4 2.5 m/s2

A force of 10 N acts perpendicular to a spanner at a distance of 0.5 m from the nut. What torque is produced?

• 1 20 N m
• 2 5 N m
• 3 0.05 N m
• 4 10 N m

A skater spinning with arms outstretched pulls her arms in. Her angular velocity:

• 1 Decreases
• 2 Stays the same
• 3 Becomes zero
• 4 Increases

A 2 kg ball moving at 3 m/s collides head-on and elastically with a stationary 2 kg ball. What happens?

• 1 Both move at 1.5 m/s
• 2 The first ball stops and the second moves at 3 m/s
• 3 Both stop
• 4 The first ball rebounds at 3 m/s

How much energy is stored in a spring of constant 200 N/m stretched by 0.1 m?

• 1 1 J
• 2 10 J
• 3 20 J
• 4 0.1 J