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