BITSAT Physics Motion In A Plane MCQs

Question: Given that A + B = R and A = B = R. What should be the angle between A and B ?

• a) 0
• b) π/3
• c) 2π/3
• d) π

Answer: 2π/3

Question: Two projectiles A and B thrown  with speeds in the ratio 1 : acquired the same heights. If A is thrown at an angle of 45° with the horizontal, the angle of projection of B will be

• a) 0°
• b) 60°
• c) 30°
• d) 45°

Answer: 30°

Question: A stone projected with a velocity u at an angle θ with the horizontal reaches maximum height H₁. When it is projected with velocity u at an angle with the horizontal, it reaches maximum height H2. The relation between the horizontal range R of the projectile, heights H¹ and H² is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The position of a projectile launched from the origin at t = 0 is given by  mat t = 2s. If the projectile was launched at an angle θ from the horizontal, then θ is (take g = 10 ms^–2)

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: A projectile is fired with a velocity u making an angle θ with the horizontal. What is the magnitude of change in velocity when it is at the highest point –

• a) u cos θ
• b) u
• c) u sin θ
• d) u cos θ – u

Answer: u sin θ

Question: The velocity and acceleration vectors of a particle undergoing circular motion are  respectively at an instant of time. The radius of the circle is –

• a) 1m
• b) 2m
• c) 3m
• d) 4m

Answer: 1m

Question: A body is projected, making an acute angle with the horizontal. If angle between velocity  r and acceleration  r is θ, then

• a) θ= 90º
• b) θ= 0º
• c) 90º < θ < 0º
• d) 0º < θ < 180º

Answer: 0º < θ < 180º

Question: When a particle is in uniform circular motion it does not have

• a) Radial velocity and radial acceleration
• b) Radial velocity and tangential acceleration
• c) Tangential velocity and radial acceleration
• d) Tangential velocity and transverse acceleration

Answer: Tangential velocity and radial acceleration

Question: The range of the particle when launched at an angle of 15º with the horizontal is 1.5 km. What is the range of the projectile when launched at an angle of 45º to the horizontal.

• a) 1.5 km
• b) 3.0 km
• c) 6.0 km
• d) 0.75 km

Answer: 3.0 km

Question: The two vectors  and  are drawn from a common point and C =  +  , then angle between  and  is –

(1) 90° if C² = A² + B²

(2) greater than 90° if C² < A² + B²

(3) greater than 90° if C² > A² + B²

(4) less than 90° if C² > A² + B²

Correct options are –

• a) 1, 2
• b) 1, 2, 3, 4
• c) 2, 3, 4
• d) 1, 2, 4

Answer: 1, 2, 4

Question: A passenger in a open car travelling at 30 m/s throws a ball out over the bonnet. Relative to the car the initial velocity of the ball is 20 m/s at 60° to the horizontal. The angle of projection of the ball with respect to the horizontal road will be

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Two projectiles A and B are thrown with the same speed but angles are 40º and 50º with the horizontal. Then

• a) A will fall earlier
• b) B will fall earlier
• c) Both will fall at the same time
• d) None of these

Answer: A will fall earlier

Question: A body is travelling in a circle at a constant speed. It

• a) Has a constant velocity
• b) Is not accelerated
• c) Has an inward radial acceleration
• d) Has an outward radial acceleration

Answer: Has an inward radial acceleration

Question: A projectile projected at an angle 30º from the horizontal has a range R. If the angle of projection at the same initial velocity be 60º, then the range will be- 

• a) R
• b) R/2
• c) 2R
• d) R²

Answer: R

Question: Given that A + B = R and A² + B² = R². The angle between A and B is 

• a) 0
• b) π/4
• c) π/2
• d) π

Answer: π/2

Question: A cannon ball has the same range R on a horizontal plane for two angles of projection. If h¹ and h² are the greatest heights in the two paths for which this is possible, then

• a) R = h¹ h²
• b)

  

• c)

  

• d)

  

Answer:

Question:  Find a vector parallel to  but has magnitude five times that of 

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: A stone is projected from the ground with velocity 25 m/s. Two seconds later, it just clears a wall 5m high. The angle of projection of the stone is (g = 10 m/sec2)

• a) 30º
• b) 45º
• c) 50.2º
• d) 60º

Answer: 30º

Question: The position vector of a particle is  The velocity of theparticle is

• a) Directed towards the origin
• b) Directed away from the origin
• c) Parallel to the position vector
• d) Perpendicular to the position vector

Answer: Perpendicular to the position vector

Question: A particle is moving in a circular path. The acceleration and momentum vectors at an instant of time are  kgm/s Then the motion of the particle is

• a) Uniform circular motion
• b) Circular motion with tangential acceleration
• c) Circular motion with tangential retardation
• d) We cannot say anything about a and p only.

Answer: We cannot say anything about a and p only.