intro
Question 1:
What is the acceleration of a projectile at its apex?
Topic: Projectile Motion
Correct Answer: D) g
- The acceleration of a projectile at any point in its trajectory, even at its apex, is always equal to 'g', acceleration due to gravity.
- Regardless of its position, the only force acting on the projectile (assuming no air resistance) is gravity, which pulls it downward with a constant acceleration.
- Thus, the correct answer is D, 'g'.
Question 2:
In all collision scenarios, which parameter remains conserved?
Topic: Principles of Conservation in Collisions
Correct Answer: D) Both A & B
- In the world of physics, certain parameters remain conserved in collision scenarios.
- The conservation of total energy and momentum is a fundamental principle that holds true in all types of collisions.
- The correct answer is therefore D, 'Both A & B'.
Question 3:
In a scenario where a particle has been moving for a period of time, which of the following can have a zero value?
Topic: Concepts of Distance and Displacement
Correct Answer: B) Displacement
- While a particle is moving, both distance and displacement are calculated, but they aren't always equal.
- Displacement takes into account initial and final positions, and can be zero if they coincide - even with the particle in motion.
- Thus, the correct answer is B, 'Displacement'.
Question 4:
Imagine a scenario where a large vehicle moving at a speed of 20 ms-1 collides head-on with a small, stationary stone. What would be the velocity of the stone post-collision?
Topic: Elastic Collisions
Correct Answer: D) 40 ms-1
- In elastic collisions involving two bodies of significantly different masses, the velocity of the lighter body post-collision is often remarkably different from its initial state.
- In this specific scenario, the principle of conservation of momentum combined with the properties of elastic collisions lead to a peculiar outcome - the stone’s velocity after the collision is twice the initial velocity of the vehicle.
- Consequently, the correct answer is D, '40 ms-1'.
Question 5:
What does the unit 'electron volt' represent?
Topic: Units of Measurement
Correct Answer: C) Energy
- An electron volt (eV) is a unit of energy important in atomic and nuclear physics.
- It is the amount of kinetic energy gained by an electron accelerating through an electric potential difference of one volt.
- Hence, the correct answer is C, "Energy".
Question 6:
Which law lies at the foundation of the concept of perpetual motion?
Topic: Laws of Motion
Correct Answer: A) Newton's 1st law of motion
- Perpetual motion involves continuous movement without external forces, conceptually related to Newton's 1st law of motion.
- According to the law of inertia, an object in motion remains in motion unless acted upon by an external force.
- Therefore, the correct answer is A, "Newton's 1st law of motion".
Question 7:
When a body free falls from rest and reaches a point where its velocity equals its displacement, what is the velocity of the body at that instant?
Topic: Kinematics in One Dimension
Correct Answer: B) 19.6 m/s
- To solve this, use the motion equation v^2 = u^2 + 2as, with gravity as the acceleration and initial velocity as zero.
- As v equals s in this scenario, the equation simplifies, allowing us to solve for v with the given gravitational constant.
- Therefore, the correct answer is B, '19.6 m/s'.
Question 8:
Suppose the initial speed of a projectile is lessened to half while keeping the projection angle constant. How would this affect the peak elevation it reaches?
Topic: Projectile Motion
Correct Answer: B) It will be reduced to a quarter
- The peak height of a projectile is related to the square of its initial velocity.
- Reducing the initial speed to half results in the height reaching a quarter of its original value.
- Therefore, the correct answer is B, 'It will be reduced to a quarter'.
Question 9:
A particle moves in a straight line and returns to its starting point after 10 seconds, covering a total distance of 30m. Which of the following assertions about the particle's movement is correct?
Topic: Motion in One Dimension
Correct Answer: D) Both A and B
- The displacement between a particle's initial and final positions is the shortest distance. Here, as the particle returns to its starting point, its displacement is zero.
- Average speed is calculated by total distance covered divided by the total time taken. Given that the particle covered 30m in 10s, its average speed is indeed 3ms-1.
- Therefore, the correct answer is D, 'Both A and B'.
Question 10:
What will the path of a projectile look like in an environment with no gravity?
Topic: Projectile Motion in Vacuum
Correct Answer: A) Linear
- Gravity is the force that changes the path of a projectile from a straight line to a curve, as it pulls the projectile towards the ground.
- In absence of gravity, there is no force to change the velocity of the projectile, so it will continue in a straight line.
- Therefore, the correct answer is A, 'Linear'.
Question 11:
How is the horizontal reach of a projectile connected to its maximum range?
Topic: Projectile Range
Correct Answer: D) Not related
- The horizontal range and maximum range of a projectile are two different concepts.
- Horizontal range refers to the total horizontal distance covered by the projectile, while maximum range refers to the furthest distance from the starting point that the projectile reaches at its peak.
- There is no direct mathematical relationship between the two, therefore, the correct answer is D, "Not related".
Question 12:
When a shot is discharged at an angle of 60 degrees from the horizontal plane, carrying an initial kinetic energy E, and devoid of any air resistance, what will be the kinetic energy at the pinnacle of its trajectory?
Topic: Kinetic Energy of Projectile
Correct Answer: C) E/4
- The kinetic energy (KE') at the top of the trajectory is given by KE' = ½mv²cos²θ.
- In this case, θ is 60 degrees, thus KE' = KE(cos 60)².
- After calculating, we find that KE' is equal to KE/4.
- Therefore, the correct answer is C, 'E/4'.
Question 13:
Consider two projectiles that are launched with the identical speed but at different angles, 60 degrees and 30 degrees respectively. For these two projectiles, which characteristic remains constant?
Topic: Projectile Motion
Correct Answer: B) Range
- When two projectiles are launched with the same speed but at complementary angles, their respective ranges will be equivalent.
- This is due to the symmetry of the projectile motion at complementary angles such as 60° and 30°.
- Therefore, the correct answer is B, 'Range'.
Question 14:
A sphere is launched at an angle of 45 degrees relative to a flat surface. If the horizontal distance covered by the sphere is 20m, what is the maximum altitude the sphere is able to reach? (Assume g = 10m/s2)
Topic: Projectile Height
Correct Answer: B) 5.0m
- The maximum height in projectile motion at an angle of 45 degrees is h = u²sin²θ / 2g.
- With the given range, we can solve for the initial speed u, then find the maximum height.
- The correct answer is B, '5.0m'.
Question 15:
If you are strolling at a uniform velocity of 8 km/h and a vehicle overtakes you from behind at a speed of 30 km/h, what is the velocity of the car relative to you?
Topic: Relative Velocity
Correct Answer: B) 22 km/h
- Relative velocity is the velocity of one object as observed from another.
- In the same direction, we subtract the observer's speed from the other object's speed.
- Thus, the correct answer is B, '22 km/h'.
Question 16:
Which of the following expressions accurately represents the power exerted?
Topic: Power Exerted
Correct Answer: A) Fcosθv
- Power is the scalar product of force and velocity in the context of force at an angle to velocity.
- The power exerted is given by P = Fv cosθ.
- Therefore, the correct answer is A) Fcosθv.
Question 17:
A particle is moving in a plane, experiencing a constant acceleration in a direction that is not aligned with the initial velocity. What will be the trajectory of the particle?
Topic: Particle Motion
Correct Answer: C) A parabola
- If a particle possesses constant acceleration in a direction that is not aligned with its initial velocity, the resulting motion is parabolic.
- This is because the component of velocity that is perpendicular to the acceleration remains constant while the component of velocity parallel to the acceleration changes linearly with time.
- Therefore, the correct answer is C, 'A parabola'.
Question 18:
What does the area under an acceleration-displacement curve for a body represent?
Topic: Acceleration-Displacement Curve
Correct Answer: D) Variation in kinetic energy per unit mass
- The area under an acceleration-displacement graph represents the change in kinetic energy per unit mass.
- This is derived from the equation for kinetic energy, which is the work done on the object, and can be represented as the area under a force-displacement curve.
- Therefore, the correct answer is D, 'Variation in kinetic energy per unit mass'.
Question 19:
The body travels from point A to point B at a speed of 30km per hour, then returns from B to A at a speed of 40 km/hr. Over the course of the journey, what is the average velocity of the body?
Topic: Average Velocity
Correct Answer: D) None of These
- Total displacement divided by total time is calculated as average velocity.
- In this case, the body returns to its starting point, so the total displacement is zero.
- Therefore, the average velocity for the entire journey is zero, meaning correct answer is D, 'None of These'.
Question 20:
What is the numerical relation between a particle's velocity and speed?
Topic: Velocity and Speed Ratio
Correct Answer: A) Equal to or less than one
- Velocity is a vector quantity, indicating direction, while speed is a scalar quantity, not dependent on direction.
- Since displacement (used to calculate velocity) is always less than or equal to distance (used to calculate speed), the ratio of velocity to speed is always less than or equal to one.
- Hence, the correct answer is A, 'Equal to or less than one'.
Question 21:
If R represents the furthest horizontal reach of a projectile, what is the highest point achieved by the projectile under these conditions?
Topic: Projectile Motion
Correct Answer: D) R/4
- The relationship between the maximum height (H) and range (R) of a projectile is given by the formula 4H = R tanθ.
- When the launch angle (θ) is 45°, the range is maximized, tan45° equals 1.
- So, we get H = R/4. Hence, the correct answer is D, 'R/4'.
Question 22:
If a ball is dropped freely from a certain height, what distance does it cover in the first second?
Topic: Free Fall Distance
Correct Answer: B) g/2
- In free fall, the distance covered by an object is determined by the equation of motion: d = 1/2gt^2, where g is gravity's acceleration and t is time.
- Substituting t = 1 second, we get d = 1/2g.
- Thus, the correct answer is B, 'g/2'.
Question 23:
From the window of a train in motion, a coin is dropped. What would the motion path of the coin look like from the perspective of a stationary observer inside the train?
Topic: Motion of a falling object
Correct Answer: A) A straight line descending vertically
- The trajectory of an object in free fall, as seen by an observer inside the train (which is the reference frame of the object), will always appear to be a straight line.
- The object will follow a projectile motion path from the perspective of an observer outside the train, due to the combined horizontal motion of the train and vertical motion of the coin.
- Therefore, the correct answer is A, 'A straight line descending vertically'.
Question 24:
When a projectile is launched at an angle of 30° with momentum p, ignoring air resistance, what is the change in kinetic energy when it lands back on the ground?
Topic: Kinetic Energy in Projectiles
Correct Answer: D) None of These
- In a system without energy loss (like air resistance), the total mechanical energy is conserved, which means the change in kinetic energy plus the change in potential energy equals zero.
- As the projectile returns to the same level, the change in potential energy is zero. Therefore, the change in kinetic energy is also zero.
- Hence, the correct answer is D, 'None of These'.
Question 25:
A cyclist on a circular track with a radius of 40m completes half a rotation in 40 seconds. What is the cyclist's average velocity?
Topic: Average Velocity in Circular Motion
Correct Answer: C) 2 ms−1
- Average velocity is defined as the total displacement over the total time.
- In circular motion, if the object returns to its starting point, the displacement is zero and so is the average velocity.
- However, in this case, the cyclist only completes half a rotation, so the displacement is the diameter of the circle (2*40m = 80m) and the time is 40 seconds.
- Therefore, the average velocity is 80m/40s = 2 ms−1, making C the correct answer.
Question 26:
A man can hurl a rock to a maximum distance of 100 meters. With the same conditions applied, what would be the maximum altitude he can toss the stone to?
Topic: Maximum Height of Thrown Object
Correct Answer: D) 25 m
- The maximum distance, or range, of a projected object is achieved at a launch angle of 45 degrees.
- The maximum height is reached when the object is thrown straight up (90 degrees).
- Since both actions are done under the same conditions, the maximum height will be a quarter of the maximum range.
- Therefore, the answer is D, '25 m'.
Question 27:
Which among the following angles of projection offers the maximum height for a launched projectile?
Topic: Optimal Projection Angle for Maximum Height
Correct Answer: D) 75°
- A projectile reaches the highest altitude at a launch angle of 90 degrees.
- Among the provided options, the angle closest to 90 degrees will yield the maximum height.
- Therefore, the correct answer is D, '75°'.
Question 28:
What is the dimensionality of a projectile's motion?
Topic: Dimensions of Projectile Motion
Correct Answer: C) Two
- A projectile's motion can be broken down into two independent components: horizontal and vertical motion.
- The combination of these two motions gives the projectile its characteristic parabolic trajectory.
- Therefore, the motion of a projectile is two-dimensional, making the correct answer C, 'Two'.