Why is magnetic force a non contact force?

which of newton's three laws of motion allows us to determine the force required to do work on an object?

A person pours 330 g of water at 90°C into an 855-g aluminum container with an initial temperature of 10°C. The specific heat of aluminum is 900 J / (kg·K) and that of water is 4190 J / (kg·K).

A 70kg box is slid along the floor by a 400n force. The coefficient of friction between the box and the floor is 0.5 when the box is sliding. Find the acceleration of the box

Astronaut rachel leaves earth in a spaceship at a speed of 0.960c relative to an observer on earth. rachel's destination is a star system 14.4 light-years away (one light-year is the distance light travels in one year).

A U-shaped tube open to the air at both ends contains some mercury. A quantity of water is carefully poured into the left arm of the Ushaped tube until the vertical height of the water column is 15.0 cm.

At what temperature did the substance in the test tube into a solid?

What occurs when the velocity of Earth is doubled? a. The orbit of Earth around the Sun becomes smaller b. The orbit of Earth does not change c. The Earth escapes the Sun d. The orbit becomes more elliptical

When is a body said to be at rest

27. Calculate the impulse when an average force of 10 N acts on a cart for 5.0 s.

A boy on a bicycle is resting at the top of a hill then he rides his bicycle down the hill describe how the boy potential and kineti energy differ at the top middle and bottom of the him