Which chemical reaction absorbs energy?

photosynthesis

explosion

current produced by a battery

combustion of fuels

activated hand warmers

Which has greater kinetic energy: a bullet that has a mass of 0.05 kg travelling at 2500 m/s, or a lorry that has a mass of 4500 kg and is moving at 50 m/s?

A car slows down uniformly from a speed of 28.0 m/s to rest in 8.00 s. How far did it travel in that time?

A 1.20 g sample of an unknown has a volume of 1.73 cm what is the density of the unknown

A projectile (mass = 0.226 kg) is fired at and embeds itself in a target (mass = 2.04 kg). (the target is initially stationary). the target (with the projectile in it) flies off after being struck.

Which of the following has the most thermal energy? 1. A 1/2 liter mug of hot chocolate at 75 degrees 2. A 1 liter mug of hot chocolate at 75 degrees 3. They have the same amount of thermal energy because they are both at 75 degrees 4.

Janice has just measured the density of an object. Which value is possible? (Density: D = )

Based on how the book describes a heat pump in sec 16.3 how does a heat pump prove law of conservation of energy

When a gas in a container is squeezed to half its volume, its density?

A ballet student with her arms and a leg extended spins with an initial rotational speed of 0.90rev/s. As she draws her arms and leg in toward her body, her rotational inertia becomes 0.80 kg⋅m2 and her rotational velocity is 4.1rev/s.

The power rating of a vacuum cleaner is 0.8 kilowatts. If you use the vacuum cleaner for 2.5 hours, how much energy does it use?