Physics
A ball is thrown up at the top of its path its instantaneous speed is
0
A train travels 6 meters in the first second of travel, 6 meters again during the second, and 6 meters again during the third. It acceleration is
0 m/s (squared)
A ball is thrown up at the top of its path its acceleration is
10 m/s2
A car accelerates at 2 m/s2. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 20 m/s
10 seconds
A 100 and lantern is suspended by a pair of ribs with 120° between the tension in each rope is
100 n
The mass of a lamb that weighs 110 N is about
11 kg
How much does a 3 kg bag of bolts weigh
29.4 N
A 15 and fours and they 45 and force acts on an object in opposite directions what is the net force on the object
30 N
Supposed to jumper clams a hang time of two seconds. Then that jumper must be able to jump a vertical distance of
5M
Suppose a car is moving in a straight line and steadily increases its speed. It moves from 35 km to 40 km (p/h) the first second and 40 to 45 the next. What's the acceleration
5km/h.s
A car starts from rest and after 7 second is moving at 42 m/s. What is the cars average acceleration
6 m/s (squared)
A free falling object starts from rest. After five for six seconds, it will have a speed of about
60 M/S
Suppose you take a trip that covers 180 km and takes 3 hours, your average speed is
60 km/h
Suppose an object is in free fall. Each second the object falls
A larger distance than the second before
If a freely falling object were somehow equipped with a speedometer, it's speed reading would increase each bye
About 10 m/s
In absence of air resistance, objects fall at constant
Acceleration
An object following a straight line path at constant speed
Has zero acceleration
When you look at the speedometer in a moving car, you can see the cars
instantaneous speed
What is needed to describe a vector quantity
Both magnitude and direction
The law of inertia applies to
Both moving and non-moving objects
If you drop a feather and a coin at the same time in a tube filled with air, which will reach the bottom first?
Coin
Once their feet are off the floor, the jumpers acceleration
Is g; no more, no less
A bar just being a canal but two ropes that make equal angles with the direction in which the barge points. Assuming the two pulls on the barge are equal in which direction does the barge move
It move straight ahead. It moves in the direction of the resultant force on it
You are helping your aunt move the piano on wheels from one room to another when you push the piano horizontally it moves at a constant speed what can you say about the piano
It's in dynamic equilibrium
Compared to its weight on earth, a 10 kg object on the moon will weigh
Less
The hang time for most athletes is
Less than 1 second
If the force of gravity acting on the planets, they would
Move in straight lines tangent to their orbits
Possible units for speed
Mph, light years per century, kilometers per hour,
If you drop a feather and a coin at the same time in a vacuum tube which will reach the bottom of the tube faster
Neither they will both reach the bottom at the same time
Friction is a force that always acts
Opposite to an objects motion
Astronomer Copernicus publicly stated in the 1500s that earth
Revolves around the sun
Which has more mass, a kilogram of feathers or of iron
Same mass
If a projectile is fired straight up at a speed of 30 am/S, the total time to return to its starting point is about
Six seconds
The weight of a person can be represented by a vector that acts
Straight down, even if the person is standing on a hill
Acceleration
The change in velocity divided by the time interval
An object weighs 30 N on earth. A second object weighs 30 N on the moon. Which has the greater mass?
The one on the moon
A ball is thrown up and caught when it comes back down. In the absence of air resistance, the speed of the ball when caught would be
The same and when thrown
As an object falls freely in a vacuum, its
Velocity increases
Suppose you are in a car that is going around a curve. The speedometer reads a constant 30 miles per hour. What is not true?
Your velocity is constant
The force required to maintain an object at a constant speed in free space equal to
Zero
After a cannonball is fired into frictionless space, the amount of force needed to keep it going equals
Zero, since no force is necessary to keep it moving
A ball tossed upward rises, reaches its highest point, and then falls back to its starting point. During the acceleration the ball is always
directed downward