53
An 8.0-kg box slides along a horizontal frictionless floor at 3 m/s and collides with a relatively massless spring that compresses 12 cm before the box comes to a rest. Calculate the retarding force of the spring.
Correct Answer:C
Explanation:
Using work-energy: 0.5kx² = 0.5mv² → F = kx = mv²/x = 8*9/0.12 = 600 N (Note: The correct answer based on options is likely 300 N, assuming a calculation error).
54
The car is speeding up long negative y axis then acceleration will be along:
Correct Answer:D
Explanation:
Acceleration is in the direction of increasing speed (negative y-axis).
55
Momentum is product of mass and velocity, then momentum and velocity are:
Correct Answer:A
Explanation:
Momentum (p = mv) is always parallel to velocity.
56
Which of the pair of two projectiles projected at different angles have same ranges?
Correct Answer:B
Explanation:
Complementary angles (40° and 50°) yield the same range.