A 2.5 kg block lies on a frictionless 37° incline of a wedge attached to a horizontal spring balance. All surfaces are smooth; source states wedge is in equilibrium. If spring-balance reading is (10+x) N, find x.
Physics · Mixed Chapter
JEE Main Practice

Question

A 2.5 kg block lies on a frictionless 37° incline of a wedge attached to a horizontal spring balance. All surfaces are smooth; source states wedge is in equilibrium. If spring-balance reading is (10+x) N, find x.

Physics · Mixed Chapter

G1 Physics · Accepted Answer

Step 1: The block normal component on an incline is N = mg cos37° = 2.5×10×4/5 =20 N when the wedge is stationary. Step 2: Horizontal contact force on wedge = N sin37° = 20×3/5 =12 N. Step 3: This gives 10+x=12 ⇒x=2, not PDF key x=4. Moreover, with a fixed smooth incline a block cannot stay at rest along it without an additional balancing force. Step 4: Retain the source answer 4 only as an unverified printed key.