Q. A 2 kg object is moving with a velocity of 3 m/s. What is its kinetic energy?
A.9 J
B.6 J
C.3 J
D.12 J
Solution
Kinetic energy is given by KE = 0.5 * m * v² = 0.5 * 2 kg * (3 m/s)² = 9 J.
Correct Answer: A — 9 J
Q. A ball is thrown vertically upwards with a speed of 20 m/s. How high will it go before it starts to fall back down? (g = 10 m/s²)
A.20 m
B.30 m
C.40 m
D.10 m
Solution
Using the formula v² = u² + 2as, where v = 0, u = 20 m/s, and a = -10 m/s², we get 0 = 20² + 2 * (-10) * s, solving gives s = 20 m.
Correct Answer: B — 30 m
Q. A car accelerates from rest at a rate of 2 m/s². How far does it travel in 5 seconds?
A.25 m
B.20 m
C.10 m
D.15 m
Solution
Using the formula s = ut + 0.5at², where u = 0, a = 2 m/s², and t = 5 s, we get s = 0 + 0.5 * 2 * 5² = 25 m.
Correct Answer: A — 25 m
Q. A car moving at 60 km/h applies brakes and comes to a stop in 5 seconds. What is the distance covered during braking?
A.50 m
B.60 m
C.70 m
D.40 m
Solution
Convert speed to m/s: 60 km/h = 16.67 m/s. Using s = ut + 0.5at², where a = (0 - 16.67)/5 = -3.33 m/s², we find s = 16.67 * 5 + 0.5 * (-3.33) * 5² = 41.67 m.
Correct Answer: A — 50 m
Q. A car travels 100 meters in 4 seconds. What is its average speed?
A.25 m/s
B.20 m/s
C.15 m/s
D.30 m/s
Solution
Average speed = total distance / total time = 100 m / 4 s = 25 m/s.
Correct Answer: B — 20 m/s
Q. A cyclist travels at a speed of 15 m/s. How long will it take to cover a distance of 300 meters?
A.20 s
B.15 s
C.25 s
D.10 s
Solution
Using the formula time = distance/speed, we have time = 300 m / 15 m/s = 20 s.
Correct Answer: A — 20 s
Q. A projectile is launched at an angle of 30 degrees with an initial speed of 40 m/s. What is the maximum height reached? (g = 9.8 m/s²)
A.80 m
B.60 m
C.40 m
D.20 m
Solution
The vertical component of the velocity is 40 * sin(30) = 20 m/s. Using h = (v²)/(2g), we get h = (20²)/(2 * 9.8) ≈ 20.41 m.
Correct Answer: B — 60 m
Q. A projectile is launched at an angle of 30 degrees with an initial velocity of 20 m/s. What is the horizontal component of its velocity?
A.10 m/s
B.17.32 m/s
C.20 m/s
D.5 m/s
Solution
The horizontal component is given by v_x = v * cos(θ) = 20 * cos(30°) = 20 * (√3/2) ≈ 17.32 m/s.
Correct Answer: B — 17.32 m/s
Q. A train moving at 72 km/h applies brakes and comes to a stop in 10 seconds. What is the deceleration?
A.2 m/s²
B.3 m/s²
C.4 m/s²
D.5 m/s²
Solution
First convert speed to m/s: 72 km/h = 20 m/s. Using a = (v - u)/t, we have a = (0 - 20)/10 = -2 m/s², so deceleration = 2 m/s².
Correct Answer: C — 4 m/s²
Q. An object is in free fall from a height of 80 m. How long will it take to reach the ground? (g = 9.8 m/s²)
A.4 s
B.5 s
C.6 s
D.3 s
Solution
Using the formula s = ut + 0.5gt², where u = 0, s = 80 m, and g = 9.8 m/s², we solve 80 = 0 + 0.5 * 9.8 * t², giving t ≈ 4.04 s.
Correct Answer: B — 5 s
Q. An object is thrown horizontally from a height of 45 m. How long does it take to hit the ground? (g = 9.8 m/s²)
A.3 s
B.4 s
C.5 s
D.2 s
Solution
Using the formula s = 0.5gt², we have 45 = 0.5 * 9.8 * t², solving gives t ≈ 3.03 s.
Correct Answer: B — 4 s
Q. If a ball is thrown vertically upward with an initial velocity of 15 m/s, how high will it go before coming to a stop?
A.11.47 m
B.15 m
C.7.5 m
D.20 m
Solution
Using the formula h = v²/(2g), where v = 15 m/s and g = 9.81 m/s², we find h = (15)²/(2*9.81) ≈ 11.47 m.
Correct Answer: A — 11.47 m
Q. If a car accelerates from rest at a rate of 2 m/s², what is its velocity after 5 seconds?
A.10 m/s
B.5 m/s
C.15 m/s
D.20 m/s
Solution
Using the formula v = u + at, where u = 0, a = 2 m/s², and t = 5 s, we get v = 0 + (2)(5) = 10 m/s.
Correct Answer: A — 10 m/s
Q. If a car travels 100 meters in 5 seconds, what is its average speed?
A.20 m/s
B.25 m/s
C.15 m/s
D.30 m/s
Solution
Average speed is calculated as total distance divided by total time: 100 m / 5 s = 20 m/s.
Correct Answer: B — 25 m/s
Q. In a frictionless environment, if a 5 kg block is pushed with a force of 20 N, what will be its acceleration?
A.4 m/s²
B.2 m/s²
C.5 m/s²
D.0 m/s²
Solution
Using F = ma, we have 20 N = 5 kg * a, thus a = 20 N / 5 kg = 4 m/s².
Correct Answer: A — 4 m/s²
Q. What is the acceleration of an object in free fall near the Earth's surface?
A.9.81 m/s²
B.0 m/s²
C.1.62 m/s²
D.32.2 ft/s²
Solution
The acceleration due to gravity near the Earth's surface is approximately 9.81 m/s².
Correct Answer: A — 9.81 m/s²
Q. What is the center of gravity of a uniform beam of length L?
A.0
B.L/2
C.L
D.L/4
Solution
For a uniform beam, the center of gravity is located at its midpoint, which is L/2.
Correct Answer: B — L/2
Q. What is the formula for calculating the frictional force?
A.F_friction = μN
B.F_friction = m*a
C.F_friction = N/g
D.F_friction = v/t
Solution
The frictional force is calculated using the formula F_friction = μN, where μ is the coefficient of friction and N is the normal force.
Correct Answer: A — F_friction = μN
Q. What is the net force acting on a 10 kg object that is accelerating at 3 m/s²?
A.30 N
B.10 N
C.3 N
D.0 N
Solution
Using Newton's second law, F = ma, we find F = 10 kg * 3 m/s² = 30 N.
