WCU PHYS 261 Final Exam ACTUAL EXAM 2026/2027: 100% Verified Questions & Correct Answers

WCU PHYS 261 Final Exam ACTUAL
EXAM 2026/2027: 100% Verified
Questions & Correct Answers

Question 1: A car accelerates uniformly from rest to 25 m/s in 5.0 seconds. What is the magnitude
of its acceleration?
A. 5.0 m/s²
B. 125 m/s²
C. 0.20 m/s²
D. 30 m/s²
Correct Answer: A


Rationale: Using a = Δv/Δt = (25 m/s - 0 m/s)/(5.0 s) = 5.0 m/s²

Question 2: A ball is thrown vertically upward with an initial velocity of 20 m/s. What is the maximum
height it reaches? (g = 9.8 m/s²)
A. 20.4 m
B. 40.8 m
C. 10.2 m
D. 2.04 m
Correct Answer: A


Rationale: Using v² = v₀² + 2aΔy, at max height v = 0, so 0 = (20)² + 2(-9.8)Δy, solving gives Δy =
20.4 m

Question 3: According to Newton's First Law, an object in motion will:
A. Always come to rest eventually
B. Continue in motion with constant velocity unless acted upon by a net force
C. Accelerate continuously
D. Slow down due to friction
Correct Answer: B

,Rationale: Newton's First Law states that an object in motion will remain in motion with constant
velocity unless acted upon by a net external force.

Question 4: A 10 kg box is pulled across a frictionless surface by a 20 N horizontal force. What is
its acceleration?
A. 2.0 m/s²
B. 0.5 m/s²
C. 200 m/s²
D. 0.2 m/s²
Correct Answer: A


Rationale: Using Newton's Second Law: F = ma, so a = F/m = 20 N/10 kg = 2.0 m/s²

Question 5: A 5.0 kg object experiences a net force of 15 N. What is its acceleration?
A. 3.0 m/s²
B. 0.33 m/s²
C. 75 m/s²
D. 1.5 m/s²
Correct Answer: A


Rationale: Using F = ma, acceleration = F/m = 15 N/5.0 kg = 3.0 m/s²

Question 6: A projectile is launched at 45° above the horizontal with initial speed 20 m/s. What is its
horizontal component of velocity? (Neglect air resistance)
A. 14 m/s
B. 20 m/s
C. 10 m/s
D. 7.1 m/s
Correct Answer: A


Rationale: Horizontal component: vₓ = v cos θ = (20 m/s)(cos 45°) = (20 m/s)(0.707) = 14 m/s

Question 7: A 2.0 kg block slides down a frictionless 30° incline. What is its acceleration along the
incline? (g = 9.8 m/s²)
A. 4.9 m/s²
B. 9.8 m/s²
C. 2.0 m/s²
D. 8.5 m/s²
Correct Answer: A


Rationale: Component of g along incline: a = g sin θ = (9.8 m/s²)(sin 30°) = (9.8 m/s²)(0.5) = 4.9
m/s²

, Question 8: A car rounds a curve of radius 50 m at constant speed 20 m/s. What is its centripetal
acceleration?
A. 8.0 m/s²
B. 0.40 m/s²
C. 1000 m/s²
D. 2.5 m/s²
Correct Answer: A


Rationale: Centripetal acceleration: a = v²/r = (20 m/s)²/(50 m) = 400/50 = 8.0 m/s²

Question 9: A 0.50 kg ball moving at 4.0 m/s strikes a wall and rebounds at 3.0 m/s. If contact time
is 0.10 s, what is the average force exerted by the wall?
A. 35 N
B. 5.0 N
C. 15 N
D. 1.5 N
Correct Answer: A


Rationale: Impulse = Δp = m(v_f - v_i) = 0.50 kg(3.0 - (-4.0)) m/s = 3.5 kg·m/s; F = Δp/Δt = 3.5/0.10
= 35 N

Question 10: A 60 kg runner accelerates from rest to 8.0 m/s in 2.0 s. What average power is
required?
A. 960 W
B. 240 W
C. 480 W
D. 1920 W
Correct Answer: A


Rationale: Work = ΔKE = ½mv² = ½(60 kg)(8.0 m/s)² = 1920 J; Power = Work/t = 1920 J/2.0 s = 960
W

Question 11: A spring with constant k = 200 N/m is compressed 0.10 m. What potential energy is
stored?
A. 1.0 J
B. 2.0 J
C. 0.50 J
D. 20 J
Correct Answer: A


Rationale: PE = ½kx² = ½(200 N/m)(0.10 m)² = 1.0 J