Physics Problems

Problem: A student pushes a desk with a force of 50 N over a distance of 3 meters. How much work does the student do on the desk?

• 150 Joules

• 50 Joules

• 100 Joules

• 200 Joules

Problem: How much work is done in lifting a 10 kg backpack to a shelf 2 meters high? (Assume g = 9.8 m/s²)

• 19.6 J

• 98 J

• 196 J

• 20 J

Problem: A motor does 6000 J of work in 10 seconds. What is its power output?

• 600 W

• 6000 W

• 60 W

• 60000 W

Problem: What is the kinetic energy of a 4 kg ball moving at 5 m/s?

• 50 J

• 40 J

• 25 J

• 100 J

Problem: A 2 kg object is placed on a shelf 1.5 meters high. If g=9.8 m/s², what is its gravitational potential energy?

• 29.4 J

• 15 J

• 19.6 J

• 9.8 J

Problem: A person pulls a suitcase with a force of 100 N at an angle of 30° to the ground over 5 meters. How much work is done?

• 250 J

• 433 J

• 500 J

• 866 J

Problem: A 1 kg object has 18 J of kinetic energy. What is its speed?

• 3 m/s

• 6 m/s

• 9 m/s

• 12 m/s

Problem: A crane lifts a 500 kg object 20 meters high in 25 seconds. How much power does it use?

• 400 W

• 500 W

• 600 W

• 700 W

Problem: A roller coaster car has 10,000 J of potential energy at the top of a hill. Assuming no energy is lost to friction, how much kinetic energy will it have at the bottom?

• 10,000 J

• 5,000 J

• 0 J

• 20,000 J

A player hits a 0.15-kg baseball over the outfield fence. The ball leaves the bat with a speed of 36 m/s, and a fan in the bleachers catches it 7.2 m above the point where it was hit. Ignoring friction, find the speed of the ball just before it is caught.

• 34 m/s

• 32 m/s

• 36 m/s

• 73 m/s