In which of the following situation is work being done?

A car is pushed but does not budge.

A weightlifter holds a barbell over his head.

A wagon is pulled at an angle of 30 degrees to the horizontal.

A swimmer treads water for 15 minutes.

Why do we see lightning before we hear the accompanying Thunder

Explain nuclear fusion briefly

Fill in the blank Comets have orbits that are in the shape of an exaggerated ___ because of this we see them only when their orbit brings them into our solar system

Playing catch with a friend in a moving train. When you toss the ball in the direction the train is moving, how does the speed of the ball appear to an observer standing at rest outside the train?

A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the car. Since a lot of damage is done on the car : Select one: a. the force on the truck is smaller than the force on the car. b.

For a vacation, you and your family fly east to west from Boston, Massachusetts, to Seattle, Washington. You notice that your flight back home to Boston is shorter than your flight to Seattle. Which phenomenon causes your flight home to be shorter?

You spy on an anchor on the bottom of a lake. What is the direction and amount of force the water exerts on it: a) zero b) up, equal to the weight of the anchor. c) up, less than the weight of the anchor d) down, equal to the weight of the anchor.

How are electromagnetic waves different from matter waves?

A dc generator is the same as a (n) a. electric motor. b. ac generator. c. armature. d. electric current.

Which of the following best describes scientific knowledge A.) Durable B.) Absolute and never changing C.) Frequently varies