Crate pulled at an angle
A 20 kg crate is pulled by a 90 N force at 30° above horizontal. Friction is 25 N. Find the horizontal acceleration and the normal contact force.
TOPIC 4 · CIE PRACTICESketch the system.
Sketch the system.
Then balance it.
Attempt each visible question with a labelled diagram. Open a modelling hint if needed, then reveal the detailed solution.
Hinged sign
A uniform 120 N horizontal sign extends 1.8 m from a hinge. A vertical cable supports its outer end. Find the cable force.
Turning a steering wheel
Two opposite tangential forces of 35 N act on opposite sides of a steering wheel of diameter 0.42 m. Find the torque.
Beam with two supports
A 4.0 m uniform beam of weight 300 N rests on supports at both ends. A 500 N load is 1.0 m from the left end. Find both upward support forces.
Maximum tilt
A uniform rectangular block is 0.60 m wide and 1.20 m high. Find the tilt angle from vertical when it is just about to topple about a lower edge.
Hollow object
A metal object has mass 1.35 kg and external volume 6.0 × 10⁻⁴ m³. The metal density is 7.5 × 10³ kg m⁻³. Find the volume of the hollow space.
Changing contact area
A 720 N person stands on two shoes with total contact area 360 cm², then on one heel of area 6.0 cm². Calculate both pressures.
Two-liquid column
An open tank contains 0.40 m of oil of density 820 kg m⁻³ above 0.75 m of water. Find the gauge pressure at the bottom.