A box of mass $20 \mathrm{kg}$ sits on the floor of a lift. A second box of mass $10 \mathrm{kg}$ sits on top of the first box and a third box of mass $5 \mathrm{kg}$ sits on top of the second box. When the tension in the lift cable is $4620 \mathrm{N},$ the lift is accelerating upwards at $0.5 \mathrm{m}{\mathrm{s}}^{-2}.$

Work out the reaction between the floor of the lift and the first box.

A box of mass $20 \mathrm{kg}$ sits on the floor of a lift. A second box of mass $10 \mathrm{kg}$ sits on top of the first box and a third box of mass $5 \mathrm{kg}$ sits on top of the second box. When the tension in the lift cable is $4620 \mathrm{N},$ the lift is accelerating upwards at $0.5 \mathrm{m}{\mathrm{s}}^{-2}.$

Work out the reaction between the first box and the second box.

A box of mass $20 \mathrm{kg}$ sits on the floor of a lift. A second box of mass $10 \mathrm{kg}$ sits on top of the first box and a third box of mass $5 \mathrm{kg}$ sits on top of the second box. When the tension in the lift cable is $4620 \mathrm{N},$ the lift is accelerating upwards at $0.5 \mathrm{m}{\mathrm{s}}^{-2}.$

Work out the reaction between the second box and the third box.

The mass of a lift is $200 \mathrm{kg}$ and the maximum tension in the lift cable is $2500 \mathrm{N}.$ Work out the maximum upwards acceleration of the lift when it is empty.

The mass of a lift is $200 \mathrm{kg}$ and the maximum tension in the lift cable is $2500 \mathrm{N}.$The lift carries a load of $40 \mathrm{kg}$. Work out the contact force between the lift floor and the load.

A crate of mass $m \mathrm{kg}$ is put into a lift. The lift accelerates upwards at $a \mathrm{m}{\mathrm{s}}^{-2}.$ The mass of the lift is $M \mathrm{kg}.$

Find the tension in the lift cable.

A crate of mass $m \mathrm{kg}$ is put into a lift. The lift accelerates upwards at $a \mathrm{m}{\mathrm{s}}^{-2}.$ The mass of the lift is $M \mathrm{kg}.$

Find the contact force between the lift floor and the crate.

A box of mass $5 \mathrm{kg}$ sits in a lift. A second box of mass $3 \mathrm{kg}$ sits on the first box. The lift accelerates upwards with acceleration $0.7 \mathrm{m}{\mathrm{s}}^{-2}.$

Work out the contact force between the two boxes. The tension in the lift cable is unchanged but the boxes are swapped over, so the first box sits on the second box.

A box of mass $5 \mathrm{kg}$ sits in a lift. A second box of mass $3 \mathrm{kg}$ sits on the first box. The lift accelerates upwards with acceleration $0.7 \mathrm{m}{\mathrm{s}}^{-2}.$ The tension in the lift cable is unchanged but the boxes are swapped over, so the first box sits on the second box.

Show that this increases the contact force between the boxes.