Which action makes use of a magnetic force? A.
A person puts a bank card in an electronic reader to buy an item.

B.
A parent measures a child’s temperature by touching a thermometer to the child’s head.

C.
A store clerk finds the price of an item by moving the item over a laser light.

D.
A student measures the mass of a book using a spring scale.

How do we measure or think of speed in the united states?

Aboy with a mass 25 kg climbs into a small tree. he sits on a branch that is 2.o m above to the ground.what is his gravitational potential energy above the ground?

It's a snowy day and you're pulling a friend along a level road on a sled. you've both been taking physics, so she asks what you think the coefficient of friction between the sled and the snow is. you've been walking at a steady 1.5m/s, and the rope pulls up on the sled at a 32 ∘ angle. you estimate that the mass of the sled, with your friend on it, is 65 kg and that you're pulling with a force of 80 n .