Tension Physics Example 2

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Example 2

medium
A 5 kg5 \text{ kg} block is pulled upward by a rope with an acceleration of 3 m/s23 \text{ m/s}^2. What is the tension in the rope? Use g=9.8 m/s2g = 9.8 \text{ m/s}^2.

Solution

  1. 1
    Apply Newton's second law upward: T−mg=maT - mg = ma.
  2. 2
    T=m(g+a)=5(9.8+3)=5×12.8=64 NT = m(g + a) = 5(9.8 + 3) = 5 \times 12.8 = 64 \text{ N}
  3. 3
    The tension exceeds the weight (49 N49 \text{ N}) because the rope must both support the block and accelerate it upward.

Answer

T=64 NT = 64 \text{ N}
When an object is accelerated upward by a rope, the tension must exceed the weight to provide a net upward force. The extra force above the weight produces the acceleration.

About Tension

The pulling force transmitted through a rope, string, or cable when it is pulled taut at both ends.

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More Tension Examples

Example 1 easy

A [formula] lamp hangs from a single vertical rope. What is the tension in the rope? Use [formula].

Example 3 medium

A 5 kg mass hangs from a rope. Find the tension in the rope. (Use [formula] m/su00b2)

Example 4 medium

Two blocks ([formula] and [formula]) are connected by a rope on a frictionless table. A [formula] fo

Example 5 hard

A [formula] mass hangs from a rope over a frictionless pulley, connected to a [formula] mass on the

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