Speed and Velocity
If a car travels 150 Kilometers in 2 hours, what is its average speed in kilometers per hour?
75 kilometers per hour
A car increases its speed from 20 meters per second to 50 meters per second in 5 seconds. Whats the acceleration of the car?
acceleration=30m/s 5s=6 meters per second
What does newtons first law say?
An object at rest stays at rest unless acted on by a force.
What is the net force acting on an object with a mass of 5 kg that is accelerating at 2m/s squared?
the net force is 10 Newtons
If a person lifts a 15 kg box to a height of 2 m how much work is done against gravity?
the work done is 294 joules
A runner completes a 400-meter lap in 50 seconds. Whats the runners speed in meters per second?
8 meters per second
A bike goes from rest to a speed of 15 meters per second in 3 seconds. Whats the bikes acceleration?
Acceleration- 15m/s /3s=5 meters per second squared
What does newtons second law tell us?
More mass means more force is needed to accelerate it.
If a 10 kg box is pulled with a force of 50 N to the right and there is a frictional force of 20 and acting to the left what's the acceleration of the box?
The acceleration of the box is 3m/s squared
If a machine does 600 Joules of work and 3 seconds what's the power output?
the power output of the machine is 200 Watts
A cyclist moves 30 kilometers north in 2 hours. What is the cyclists velocouty in kilometers per hour north?
the velocity is 15 kilometers per hour north.
If you plot the distance a toy car travels over time and see a strait line going up, what does this mean?
It means the toy car is moving at a constant speed
What is momentum?
Momentum is the mass of an object times its velocity.
What is the gravitational force between two objects with masses of 5 kg and 10 kg that are 2 m apart?
Gravitational forces approximately 8 + 34 * 10 -11 Newtons
What is the kinetic energy of a 10 kg object moving at a speed of 5m/s?
The kinetic energy of an object is 125 jewels
A boat travels 100 meters east in 20 seconds. What is the boats velocity in meters per second east?
5 meters per second east
On a graph showing speed over time, what does a flat, horizontal line mean?
This means the speed is constant and not changing
How does momentum change when an object is pushed?
Momentum increases of the abject speeds up due to the push.
What is the weight of a 70 kg person on Earth where the acceleration due to gravity is 9.8 m/s^2?
one way equals 70 kg * 9.8 m/s squared equals 686 North the weight of the person is 686 newtons.
How is energy transferred when a ball is thrown into the air?
when a ball is thrown energy transfers from the hand to the ball as kinetic energy as it rises kinetic energy changes the potential energy until it reaches its peak then it falls back down-converting the potential energy into kinetic energy
Bonus!!
A car travles 60km north in 2 hours, then 80 km east in 1 hour. Whats the cars average speed and average velocity for the entire trip?
Bonus question??
A car accelerates form rest a 2m/s squared for 5 seconds, moves at a constant velocity for 10 seconds, then decelerates at 1 m/s squared to stop. Whats the total distance?
175 meters
Bonus Question!!
A 2kg cart is moving at a velocity of 3 m/s when it collides with a stationary 3 kg cart. If the collision is perfectly elastic, what are the final velocities of both carts after the collision?
The final velcocity of the 2 kg cart is 1 m/s, and the final velocity of the 3 kg cart is 4 m/s.
Bonus question!!
How does gravity affect the motion of a falling object?
the force of gravity gives the object a constant acceleration of approximately 9.8 m/s/
what happens to energy when a light bulb is turned on?
the light bulb is on electrical energy converted into light energy the light illuminates the area and the heat warms the bulb and surrounding air