Topic 7 Pushes and pulls change things — what needs James (0)

Topic 7 · Pushes and pulls change things · Type 1 · bank item PP-1 · tests FOR3-002

EasyMCQType 1 — a still thing, and either a push or pull is named or nobody touches it: what does it do

A sled sits still on flat snow, and nobody pushes or pulls it. What does the sled do?

1. a) It starts sliding on its own.
2. b) It stays still. ← key
3. c) It slides a little, then stops.
4. d) It slowly turns around.

Why it is this type: The sled is still. / Nothing pushes or pulls it. / With no push or pull, a still thing stays still. / So the sled stays still.

Recommendation: Approve as the exemplar

Topic 7 · Pushes and pulls change things · Type 2 · bank item PP-2 · tests FOR3-003

EasyMCQType 2 — a moving thing, and a push or pull AGAINST the direction it moves: what happens

A roller skate rolls across the floor, and a girl's foot pushes against its front. What happens to the skate?

1. a) It slows down. ← key
2. b) It rolls faster.
3. c) It keeps rolling in the same direction.
4. d) It changes shape.

Why it is this type: The skate rolls toward her foot. / Her foot pushes against its front, against the direction it moves. / A push against the direction a thing moves slows it down, or stops it. / So the skate slows down and stops.

Recommendation: Approve as the exemplar

Topic 7 · Pushes and pulls change things · Type 4 · bank item PP-3 · tests FOR3-005

EasyMCQType 4 — which of four described pushes or pulls changes the shape of the thing it acts on

Which of these pushes or pulls changes the shape of the thing it acts on?

1. a) pressing on a marshmallow ← key
2. b) pulling a chair across the floor
3. c) kicking a ball along the sidewalk
4. d) pulling a door shut

Why it is this type: The chair, the ball and the door keep their shapes; the pushes and pulls change how they move. / The marshmallow gets squashed when you press on it. / So pressing on the marshmallow changes its shape.

Recommendation: Approve as the exemplar

Topic 7 · Pushes and pulls change things · Type 3 · bank item PP-4 · tests FOR3-004

MediumMCQType 3 — a rolling thing is pushed from one NAMED side: in which direction does it go now

A soccer ball rolls straight along the field, and a girl's foot pushes it from its right side. In which direction does the ball go now?

1. a) It keeps going straight.
2. b) It goes off to the left. ← key
3. c) It goes off to the right.
4. d) It rolls back toward where it came from.

Why it is this type: Medium because: two ideas at once — a push from the side changes direction (this topic), and a push acts away from the pusher (Topic 5, restated in Lesson 3 (A push or pull can change direction)'s own frame), so the side named decides the new direction.

The why line (what a student reads after answering): The ball rolls straight. / Her foot pushes it from its right side. / A push acts away from the pusher, so the push sends the ball to the left. / The ball goes off to the left.

Recommendation: Approve as the exemplar

Topic 7 · Pushes and pulls change things · Type 5 · bank item PP-5 · tests FOR3-004

MediumMCQType 5 — one scene: which change did the push or pull make

A plastic bottle rolls across the picnic table, and a boy's hand pushes it from the side, so it rolls off in a new direction. Which change did his push make?

1. a) It started moving.
2. b) It slowed down or stopped.
3. c) It changed direction. ← key
4. d) It changed shape.

Why it is this type: Medium because: the four-way sort across the topic's four changes, on a fresh scene; the bank keys this type on each of the four in turn, and each generated item carries the ONE atom it keys (James, 29 Sep: one atom per item).

The why line (what a student reads after answering): The bottle was already rolling. / His hand pushed it from the side. / It rolled off in a new direction, so his push changed its direction.

Recommendation: Approve as the exemplar

Topic 7 · Pushes and pulls change things · Type 7 · bank item PP-6 · tests FOR3-003

MediumMCQType 7 — a ball is caught; a named child claims its push ran out (catalogue FOR-01): what really stopped it

Sana rolls a ball across the floor to her little brother, and he catches it. Sana says the ball stopped because its push ran out, but what really stopped it?

1. a) Its push ran out.
2. b) The floor pulled it back.
3. c) The air in the room pushed it back.
4. d) His hands pushed against it. ← key

Why it is this type: A ball does not carry a push inside it that can run out. / Her brother's hands pushed against the ball, against the direction it moved. / A push against the direction a thing moves stops it. / So his hands stopped the ball.

Recommendation: Approve as the exemplar

Topic 7 · Pushes and pulls change things · Type 9 · bank item PP-7 · tests FOR3-004

ProposedHardProposed: Type 9 — the Force Concept Inventory's kicked puck, adapted: a puck slides straight, one quick push from its left side, then let go — which drawn path does it follow

A hockey puck slides straight along the ice. A shoe gives it one quick push from its left side, then lets go. Which path does the puck follow after the push?

1. a) path J
2. b) path K
3. c) path L
4. d) path M ← key

Figure: seen from above, a puck slides up the picture (a faint dashed trail shows where it came from); a shoe touches its LEFT side; four grey dashed paths lead on from the puck with letter chips — J straight on up; K leaves in M's direction, then keeps bending round to the right; L straight to the right, level with the puck; M a new straight line slanting up and to the right.

Why: A push from the side sends the puck onto a new path: not J. / After the shoe lets go, no push acts from the side, so the new path is straight, not a curve: not K. / The puck keeps its forward motion too: not L. / Path M: a new straight path, slanting away from the shoe.

Why it is this type: Hard because: two ideas chained — a push from the side sends a moving thing onto a new path (Lesson 3 (A push or pull can change direction)'s rule) AND once the shoe has left it nothing pushes it, so the new path is straight (Lesson 3 (A push or pull can change direction)'s non-example, the untouched ball). The curve K is the FCI's circular-impetus distractor (catalogue FOR-13 "a moving thing can turn by itself"); L is the belief that the push replaces the motion instead of adding to it. Fresh against Lesson 3 (A push or pull can change direction) (the ball, the wagon, the boat), its quiz (the puck-and-stick item asks only which side; no paths are drawn) and type 3.

The why line (what a student reads after answering): James — "there are probably some great MCQs that you could probably use from the physics force concept inventory. You can sort of reuse similar diagrams and similar questions to add to the existing set" and "not exactly, tweak the wording a bit". The FCI's kicked-puck items (a puck sliding at a steady speed gets one quick kick; which path does it follow) are adapted: grade 3 wording, this course's from-above register, no force arrow on the item, four paths lettered outside the option alphabet.

Recommendation: Approve the proposed type

Topic 7 · Pushes and pulls change things · Type 10 · bank item PP-8 · tests FOR3-003

ProposedHardProposed: Type 10 — the Force Concept Inventory's impetus items, adapted: a ball rolled on grass slows and stops, nobody touches it — why

Eshe rolls a ball across the grass. Nobody touches it, and it slows down and stops. Why does the ball stop?

1. a) Its push ran out.
2. b) Earth's pull slows it down.
3. c) Something pushes against it as it rolls. ← key
4. d) A moving thing always stops by itself after a while.

Why: A moving thing does not stop by itself. Stopping needs a force too. / A ball does not carry a push inside it that can run out. / Earth pulls the ball down, not back against the direction it rolls. / So something must push against the ball, against the direction it moves: the grass pushes against it as it rolls.

Why it is this type: Hard because: the pusher is not in view. The student applies Lesson 2 (A push or pull can slow or stop things)'s rule to infer that a force must act, against two documented beliefs — catalogue FOR-01 (the push runs out) and FOR-02 (a moving thing just stops; Driver et al. 1994, the FCI impetus cluster). The key names no "friction" (Grade 4's word): "something pushes against it as it rolls" is the topic's own frame; the catalogue's FOR-08 row notes that this topic keeps the verb "pushes against". Name: Eshe (free in the course-wide register, build_tools_names.py, 29 Sep 2026).

The why line (what a student reads after answering): the FCI's impetus items (a moving thing's "force" runs out) are the documented belief this topic's Lesson 2 (A push or pull can slow or stop things) confronts by rule ("A moving thing does not stop by itself. Stopping needs a force too."); type 7 tests it with the stopper in view, this type with the stopper out of view.

Recommendation: Approve the proposed type