science
A 5-N falling object encounters 5 N of air resistance. The net force is?
0 N
A hockey puck is moving at constant speed. What's the force to keep the puck moving?
0 N
A 10-kg block is pushed with a force of 20 N against friction of 10 N. What's the acceleration?
1
An apple weighs 1-N. The magnitude of net force on the apple when it is in free-fall is
1 N
A 1-kg ball is thrown straight upward. Without air resistance, the net force on the ball is
10 N
A push on a 1-kg brick accelerates it. To equally accelerate a 10-kg brick, the force is
10 times as much
A 16-N falling object encounters 4-N of air resistance. What is the net force?
12 N
A girl pulls on a 15-kg wagon with 30 N of force. What is the acceleration of the wagon?
2 m/s2
A jet has a mass of 200,000 kg. The thrust is 400,000 N. What's the acceleration?
2 m/s2
A tow truck exerts a force of 4000 N on a car, accelerating it at 2 m/s2. What is the mass?
2000 kg
A car traveling at 22 m/s comes to an abrupt halt in .1 s. What is the deceleration?
220
On Jupiter, the acceleration due to gravity is 3x Earth's. What's the weight of a 100 kg rock?
3000 N
A car has a mass of 2000 kg and accelerates at 2 m/s2. What is the force?
4000 N
A 10-kg block sliding at 10 m/s comes to rest in 2 s. The stopping force on the block is
50 N
A block is dragged at a constant speed by 6 N of force. What's the force of friction?
6 N
The weight of .6 kg of salami is about
6.0 N
What's the speed of a box before it hits the ground if it falls off a truck moving at 30 m/s?
About 30 m/s
Tie a rock at the end of a string and whirl it in a circle. If the string breaks, the rock will
Follow a straight-line path
If you slam on the breaks in your car, you lurch forward. Why?
Inertia
An object is propelled along a straight path by a force. The mass of the object is doubled.
Its acceleration halves
Which of the following is Newton's 2nd Law of Motion?
Law of Acceleration
What is Newton's 1st Law of Motion?
Law of Inertia
An object maintains its state of motion because it has
Mass
It is just as hard to accelerate a car on the Moon as it is on Earth. Why?
Mass of the car is independent of gravity
What is an example of one that is NOT a limitation to Newton's Laws of Motion?
Objects that are on Earth that are experiencing acceleration
1 N accelerates 1 kg at the rate of 1 m/s2. If the mass is doubled and the force is doubled,
The acceleration is the same
A cloth is quickly withdrawn from under a container of milk without moving it. Why?
The milk carton has inertia
A particle is accelerated by a 10-N force. Suddenly the particle encounters 10-N of resistance.
The particle continues at a constant speed
A rock is thrown into the air. At the top of its path, its acceleration is
about 10
If the mass of an object doesn't change, a constant net force produces constant
acceleration
An object is propelled along a straight path by a force. If the net force were doubled, its
acceleration would double
An object following a straight-line path at constant speed
has zero acceleration
If an object's mass is decreasing while a constant force is applied, the acceleration
increases
A scalar involves...
just magnitude
A vector involves...
magnitude and direction
A rocket becomes easier to accelerate as it travels upward, mainly because
the mass of the rocket decreases as fuel is burned
The net force required to maintain an object at a constant velocity is
zero
