ib 6.1 & 6.2 circular motion & gravitation

Question 1

• A v a
• B v 2a
• C 2v 2a
• D 2v 4a

Question 2 A particle P is moving in a circle with uniform speed. Which one of the following diagrams correctly shows the direction of acceleration a and velocity v of the particle at one instant of time?

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Question 3 The centripetal force that causes a car to go round a bend in the road is provided by

• A the force produced by the car engine acting on the wheels.
• B the friction between the tyres and the road.
• C the weight of the car.
• D the force exerted by the driver on the steering wheel.

Question 4 The centripetal force F acting on a particle of mass m that is travelling with linear speed v along the arc of a circle of radius r is given by

• A F = v²/(mr)
• B F=mv²r
• C F = mr²v
• D F = mv²/r

Question 5

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Question 6 In Newton's universal law of gravitation, the masses are assumed to be

• A extended masses
• B masses of planets
• C point masses
• D spherical masses

Question 7 Newton's law of gravitation for the force F between two point objects of masses M and m, separated by a distance d may be written as Fd² ∝ Mm The expression may also be used for the force of attraction between the Sun and the Earth, although they are not point masses. This is because

• A the gravitational constant G is not involved in the expression.
• B the force between the Sun and the Earth is very large.
• C the separation of the Sun and the Earth is much greater than their radii.
• D the mass of the Earth is much less than the mass of the Sun.

Question 8 Gravitational field strength at a point may be defined as

• A the force on a small mass placed at the point.
• B the force per unit mass on a small mass placed at the point.
• C the work done to move unit mass from infinity to the point.
• D the work done per unit mass to move a small mass from infinity to the point.

Question 9 The acceleration of free fall of a small sphere of mass 5.0 x 10⁻³ kg when close to the surface of Jupiter is 25 ms⁻². The gravitational field strength at the surface of Jupiter is

• A 2.0 x 10-4 N kg⁻¹
• B 1.3 x 10-1 N kg⁻¹
• C 25 N kg⁻¹
• D 5.0 x 10³ N kg⁻¹

Question 10

• A
• B
• C
• D