a 45kg box of books is lifted o a bookself 1.75 m above the floor. how much work was done to lift the books?

How would a scientist go about determining if an unknown substance is an element, compound, solution, or heterogeneous mixture?

If a child ran into the road 65 to 70 feet ahead of your vehicle, what is the highest speed from which you could stop with good brakes before hitting him?

On a very muddy football field, a 120 kg linebacker tackles an 75 kg halfback. immediately before the collision, the linebacker is slipping with a velocity of 8.6 m/s north and the halfback is sliding with a velocity of 7.4 m/s east.

I left a location by 6:38am and arrived a new location by 6: 58am. How do I calculate the time spent?

What happens to a wave when reflected off a node

Car crosses the first third of the road with unknown speed and the rest of the road with the speed of 50 km/h. What is the the speed in the first third if the average speed of a car is 30km/h?

1. A car speeds up from 10.0 m/s to 45.0 m/s in 4.0 s. What is its acceleration? In your response, show your work, the given and unknown quantities, the equation, and any necessary algebra.

The greater the force exerted by the engine of a car over a set distance, the greater the change in?

How do most complex organisms get their energy?

Which is an si metric unit of measurement that is used to record the heat transfer of a solution in a classroom investigation?