Energy Calculations in Physics

The video tutorial covers thermochemistry and physics problems, including heat calculations for water and aluminum, work done by gas expansion, and energy calculations for a falling baseball and a skateboarder in a pool. The instructor explains the use of equations like q=mcΔT and work=-pΔV, and demonstrates unit conversions and energy transfer concepts.

What is the formula used to calculate the heat involved when heating a substance?

• q = mcΔT

• q = mΔT

• q = cΔT

• q = m/cΔT

If 250 grams of water is heated from 25°C to 75°C, what is the heat involved?

• 100,000 joules

• 75,000 joules

• 25,000 joules

• 52,000 joules

How do you calculate the temperature change when a material absorbs heat?

• ΔT = q/c

• ΔT = q/m

• ΔT = mc/q

• ΔT = q/(mc)

What is the temperature change when 75 grams of aluminum absorbs 250 joules of heat?

• 5.0°C

• 2.5°C

• 3.7°C

• 4.0°C

What is the formula for calculating work done by a gas when it expands?

• W = -V/P

• W = P/V

• W = PΔV

• W = -PΔV

How much can a gas expand if a piston does 50 joules of work at 2 atmospheres?

• 1.00 liters

• 0.50 liters

• 0.25 liters

• 0.75 liters

What is the total energy of a baseball dropped from a height, considering both potential and kinetic energy?

• Potential energy only

• Kinetic energy only

• Potential energy - Kinetic energy

• Potential energy + Kinetic energy

What is the potential energy of a 0.14 kg baseball at a height of 25 meters?

• 50 joules

• 34 joules

• 40 joules

• 25 joules

What is the potential energy of a 50 kg skateboarder at the top of a 3.5-meter pool?

• 2000 joules

• 1500 joules

• 1716 joules

• 1800 joules

Assuming no energy loss, what is the speed of the skateboarder at the bottom of the pool?

• 10.0 m/s

• 9.0 m/s

• 8.3 m/s

• 7.5 m/s