Physics

Which of these causes the greatest influence on the drag force? a)shape b)fluid density c) surface area d)Speed

Speed

What best describes static and kinetic friction?

Static friction increases with pulling force until movement, but kinetic friction is constant once motion takes place

A clown is launched from a cannon in the circus. The gravitational force on the clown is directed a) vertically b)perpendicular to the plane c) at an angle below the inclined plane d)parallel to the plane in the same direction at the movement of the box e)parallel to the plane in the opposite direction as the movement of the box

vertically

According to Newton's Law of Universal Gravitation, if the radius of the earth were suddenly doubled, but the mass remained the same, the acceleration due to gravity at the surface would become a) 4 times what it now is b)1/4 of what it now is c)2 times what it now is d)1/2 of what it now is e)the same as it now is

1/4 of what it now is

What is Newton's first law?

An Object at rest remains at rest and an object in constant velocity motion remains in this motion until acted upon by an external force

What is Newton's third Law?

Every action has an equal and opposite reaction

What is Newton's second law?

The acceleration produced by a net force in the direction of the net force, proportional to the net force, and inversely proportional to the mass

An object is moving forward with a constant velocity. Which statement about this object MUST be true? a)the acceleration of the object is in the forward direction b) the object is in dynamic equilibrium c) No forces are acting on the object d) the net force on the object is in the forward direction

The object is in dynamic equilibrium

A stalled car is being pushed up a hill at constant velocity by three people. The net force on the car is a) down the hill and greater than the weight of the car b) up the hill and greater than the weight of the car c)down the hill and equal to the weight of the car d)up the hill and equal to the weight of the car e)zero

Zero

Suppose you are playing hockey on a new-age ice surface for which there is no friction between the ice and the hockey puck. You wind up and hit the puck as hard as you can. After the puck loses contact with your stick, the puck will... a)speed up a little, and then slow down b)start to slow down c)not slow down or speed up d)speed up a little, then move at a constant speed

not slow down or speed up

When a parachutist jumps from an airplane, he eventually reached a constant speed, called terminal speed. Once he has terminal speed, a) the force of air drag on him is equal to zero b)the force of air drag on him is equal to g c)the force of air drag on him is equal to his weight d) his speed is equal to g e) his acceleration is equal to g

the force of air drag on him is equal to his weight

A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the car. During the collision, a) the force on the car due to the collision is much greater than the force on the truck. b)the force on the truck due to the collision is slightly greater than the force on the car. c)the car and the truck have the same magnitude acceleration d) the force on the truck due to the collision is exactly equal to the force on the car.

the force on the truck due to the collision is exactly equal to the force on the car.