1D Motion
What is the difference between speed and velocity?
Speed is a scalar quantity, while velocity is a vector quantity
A 5000kg truck and a 1000kg car are travelling at constant speeds and then collides. What is true about the Forces and acceleration on each?
5000kg truck exerts a greater force on the 1000kg car, but the acceleration will be same.
A stunt person jumps from the roof of a tall building, but no injury occurs because the person lands on a large, air-filled bag. Which one of the following BEST describes why no injury occurs?
The bag provides an impulse equal to the person's change in momentum by increasing the time of impact.
What is the kinetic energy of a 60 kg man running at 8 m/s?
1920J
How does the acceleration due to gravity change
acceleration due to gravity is a value near the surface of the Earth. In most practical situations, it is usually about 9.8 m/s
If an object has a constant velocity, what can be said about its acceleration?
The acceleration is zero
A man is whirling a 0.5 kg ball on a 1.0 m long string at 2 m/s. What is true about the force on the ball?
It pulls in, toward the center of the circle
A layer of padding is added to car dashboards because it can reduce some injuries during a collision. How does the padded dashboard make people safer?
it increases the time of impact during the collision
A bird carries a 0.2 kg apple at a height of 20 m above the ground as it flies at a velocity of 5 m/s. What is the total energy of the apple-Earth system?
39.7J
can you name a example of vector quantity in your life?
some thing with speed and direction
push/ pull is a direction
displacement
What is the average acceleration of an object that changes its velocity from 10 m/s to 30 m/s in 5 seconds?
4 m/s^2
If the car of 75kg is traveling around a curve of radius of 50m at a velocity of 15 m/s, what is the centripetal force of the car?
337N
An object has a mass of 100 kg moving at 5 m/s. What is the linear momentum of the object?
500 kg m/s
A pendulum with a mass of 0.8 kg is released 1.6 m above the ground at a velocity of 5m/s. What is the velocity of the pendulum when it hits the ground?
5.6m/s
can vectors be used to solve real-world problems, such as motion or force problems?
in motion problems, vectors can be used to represent velocities and accelerations of objects
can an object have constant speed but changing velocity?
Yes speed remains constant but the object is always changing its direction of motion. its called unifor circular motion
how do planes affect the motions of objects
forces such as external applied forces can affects motions depending if it moves at a constant
would an addition of the bag of marbles affect the velocity of the cart?
yes it would weight of The cart slowed down because it now contained more mass. The momentum of a closed, isolated system is always constant
A 7000 kg car is driving and has a kinetic energy of 2000 J. What is the velocity of the car?
0.756m/s
What factors affect the rate at which objects fall?
gravitational force acting on the object and the effects of air resistance.
can an object have zero acceleration but a non zero velocity?
Yes object moves with constant velocity the speed remains constant with no change in direction
A man is whirling a 1.5 kg ball on a 3.5 m long string at 3 m/s. What is true about the force on the ball?
3.857N
What is an object's change in momentum equal to?
change in momentum is equal to the impulse applied to the object
8 kg ball is held at rest at a height of 15 meters above the ground. What is the gravitational potential energy of the ball-Earth system?
1176J
How does air resistance impact the motion of falling objects?
air resistance on falling objects can vary depending on their size, shape. In situations where the effects of air resistance are more negative, such as in a vacuum, objects would fall without experiencing this situation to their motion.