Y10 Mechanics revision

A uniform rod rests on a pivot at its center. The rod is not attached to the pivot. Forces are then applied to the rod in four different ways, as shown. The weight of the rod can be ignored.

Which diagram shows the rod in equilibrium?

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A scalar quantity has

• magnitude and direction.

• no magnitude and no direction.

• magnitude but no direction.

• direction but no magnitude.

An object of mass 50 kg accelerates from a velocity of 2.0 m/s to a velocity of 10 m/s in the same direction.

What is the impulse provided to cause this acceleration?

• 250 N s

• 400 N s

• 850 N s

• 2500 N s

An object is acted upon by a 3 N force and by a 4 N force.

Each diagram shows the two forces.

Which diagram also shows the resultant X of these two forces?

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Four objects are each acted on by only two forces, as shown.

Which object is in equilibrium?

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A moving body undergoes a change of momentum.

What is a unit for change of momentum?

• Nm

• N/m

• Ns

• N/s

A mass of 20 kg is held stationary by a rope passing over a frictionless pulley.

What is the tension T in the rope?

• 10 kg

• 20 kg

• 100 N

• 200 N

A boat starts moving across a river at velocity v perpendicular to the river bank.

The boat encounters a current along the river of velocity u, as shown.

Which vector diagram shows the resultant velocity r of the boat?

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A ball of mass 0.50 kg falls and hits the floor at 10 m/s.

It rebounds at speed 8.0 m/s, as shown.

The collision between the ball and the floor lasts for 0.50 s.

What is the average force acting on the ball during the collision?

• 2.0 N upwards

• 2.0 N downwards

• 18 N upwards

• 18 N downwards

An object of mass 4.0 kg is moving with a velocity of 3.0 m/s in a straight line.

What is the momentum of the object?

• 0.75 kg m/s

• 1.3 kg m/s

• 12 kg m/s

• 24 kg m/s