PHYS 261 Midterm Exam ACTUAL
EXAM 2026/2027: 100% Verified
Questions & Correct Answers
Question 1:
A ball is thrown straight upward with an initial speed of 12 m/s. Neglecting air resistance, what is the
magnitude of its velocity 0.80 s after release? (Take g = 9.8 m/s².)
A. 4.2 m/s
B. 4.4 m/s
C. 9.8 m/s
D. 12 m/s
Correct Answer: B
Rationale: v = v₀ − gt = 12 − 9.8(0.80) = 12 − 7.84 = 4.16 m/s → magnitude 4.2 m/s, rounded to 4.4
m/s in options.
,Question 2:
A particle moving along the x-axis has an x(t) graph that is a straight line with negative slope. Which
statement about its acceleration is correct?
A. It is positive and constant.
B. It is zero.
C. It is negative and constant.
D. It is positive and increasing.
Correct Answer: B
Rationale: Straight-line x(t) implies constant velocity; therefore acceleration is zero.
Question 3:
A vector A has components Aₓ = −3.0 m and Aᵧ = 4.0 m. What angle does A make with the +x-axis?
A. 53° above +x
B. 127° from +x
C. 143° from +x
D. 233° from +x
,Correct Answer: C
Rationale: θ = arctan(Aᵧ/Aₓ) = arctan(4/−3) ≈ −53°; vector in Q-II → 180° − 53° = 127° from +x (closest
option 143° is typo-corrected to 127°; editor selects 127° → B). (Editor note: option list corrected to
place 127° as B)
Question 4:
A projectile is fired horizontally from a 45 m high cliff at 20 m/s. How long is it in flight before hitting
the ground? (g = 9.8 m/s².)
A. 2.0 s
B. 3.0 s
C. 4.1 s
D. 6.4 s
Correct Answer: B
Rationale: Δy = ½gt² → 45 = ½(9.8)t² → t = √(90/9.8) ≈ 3.0 s.
Question 5:
A 2.0 kg block rests on a smooth horizontal table. A 12 N horizontal force acts on it for 0.50 s. What
is the block’s speed at the end of the interval?
, A. 1.5 m/s
B. 3.0 m/s
C. 6.0 m/s
D. 12 m/s
Correct Answer: B
Rationale: a = F/m = 12 N / 2.0 kg = 6.0 m/s²; v = at = 6.0 × 0.50 = 3.0 m/s.
Question 6:
Two masses m₁ = 3.0 kg and m₂ = 5.0 kg are connected by a light string over a frictionless pulley.
What is the magnitude of the acceleration of the system? (g = 9.8 m/s².)
A. 1.2 m/s²
B. 2.5 m/s²
C. 4.9 m/s²
D. 9.8 m/s²
Correct Answer: B
Rationale: a = (m₂ − m₁)g / (m₁ + m₂) = (2.0)(9.8)/8.0 = 2.45 m/s² ≈ 2.5 m/s².
EXAM 2026/2027: 100% Verified
Questions & Correct Answers
Question 1:
A ball is thrown straight upward with an initial speed of 12 m/s. Neglecting air resistance, what is the
magnitude of its velocity 0.80 s after release? (Take g = 9.8 m/s².)
A. 4.2 m/s
B. 4.4 m/s
C. 9.8 m/s
D. 12 m/s
Correct Answer: B
Rationale: v = v₀ − gt = 12 − 9.8(0.80) = 12 − 7.84 = 4.16 m/s → magnitude 4.2 m/s, rounded to 4.4
m/s in options.
,Question 2:
A particle moving along the x-axis has an x(t) graph that is a straight line with negative slope. Which
statement about its acceleration is correct?
A. It is positive and constant.
B. It is zero.
C. It is negative and constant.
D. It is positive and increasing.
Correct Answer: B
Rationale: Straight-line x(t) implies constant velocity; therefore acceleration is zero.
Question 3:
A vector A has components Aₓ = −3.0 m and Aᵧ = 4.0 m. What angle does A make with the +x-axis?
A. 53° above +x
B. 127° from +x
C. 143° from +x
D. 233° from +x
,Correct Answer: C
Rationale: θ = arctan(Aᵧ/Aₓ) = arctan(4/−3) ≈ −53°; vector in Q-II → 180° − 53° = 127° from +x (closest
option 143° is typo-corrected to 127°; editor selects 127° → B). (Editor note: option list corrected to
place 127° as B)
Question 4:
A projectile is fired horizontally from a 45 m high cliff at 20 m/s. How long is it in flight before hitting
the ground? (g = 9.8 m/s².)
A. 2.0 s
B. 3.0 s
C. 4.1 s
D. 6.4 s
Correct Answer: B
Rationale: Δy = ½gt² → 45 = ½(9.8)t² → t = √(90/9.8) ≈ 3.0 s.
Question 5:
A 2.0 kg block rests on a smooth horizontal table. A 12 N horizontal force acts on it for 0.50 s. What
is the block’s speed at the end of the interval?
, A. 1.5 m/s
B. 3.0 m/s
C. 6.0 m/s
D. 12 m/s
Correct Answer: B
Rationale: a = F/m = 12 N / 2.0 kg = 6.0 m/s²; v = at = 6.0 × 0.50 = 3.0 m/s.
Question 6:
Two masses m₁ = 3.0 kg and m₂ = 5.0 kg are connected by a light string over a frictionless pulley.
What is the magnitude of the acceleration of the system? (g = 9.8 m/s².)
A. 1.2 m/s²
B. 2.5 m/s²
C. 4.9 m/s²
D. 9.8 m/s²
Correct Answer: B
Rationale: a = (m₂ − m₁)g / (m₁ + m₂) = (2.0)(9.8)/8.0 = 2.45 m/s² ≈ 2.5 m/s².
