ENG1011 PASS WK3- Springs and Pulleys

According to Hooke’s Law, what is the relationship between the force applied to a spring and its displacement?

• Inverse proportionality

• Direct proportionality

• Exponential relationship

• No relationship

What does the spring constant (k) represent in Hooke’s Law?

• Mass of the spring

• Stiffness of the spring

• Length of the spring

• Elasticity of the spring

If the displacement of a spring is doubled, according to Hooke’s Law, how does the force change?

• It becomes half

• It remains the same

• It doubles

• It quadruples

Consider the following system:

Both springs have a constant of 25N/m and the block is motionless. If the bottom spring is compressed 0.4m past its equilibrium and the block has a mass of 3kg, how far is the top spring stretched past its equilibrium? (let g = 10m/s^2)

• 0.4 m

• 0.6 m

• 1.0 m

• 0.8 m

A block of mass 25kg lies on a smooth horizontal table. A light inextensible string passes over a smooth pulley attached to the edge of the table. The string connects the 25kg block to another, of mass 60kg that hangs freely as shown. The system is then released from rest. Find the tension T (N) in the string and acceleration a of the system. (let g = 9.8m/s^2)

• 168 N

• 172 N

• 6.9 m/s^2

• 173 N

• 9.8 m/s^2

Consider the pulley system shown in the figure below. The mass of block B is 150 kg. Determine how far the person needs to pull down at point A in order to raise the block by 2.5 m. (Let g =

9.8 m/s^2)

• 5 m

• 10 m

• 15 m

• 2 m