Answer:
a. If an object's speed is constant, then its acceleration must be zero.
FALSE
As we know that acceleration is defined as the rate of change in velocity
so we can not say anything about the acceleration when speed is given to as and no information is given about velocity
b. If an object's acceleration is zero, then its speed must be constant.
TRUE
As we know that acceleration is defined as the rate of change in velocity
Since we know that if acceleration is 0 then velocity must be constant and hence speed is also constant
c. If an object's velocity is constant, then its speed must be constant.
TRUE
Since velocity is constant then it shows that its magnitude and direction both are constant so its speed is also constant.
d. If an object's acceleration is zero, its velocity must be constant.
TRUE
As we know that acceleration is defined as the rate of change in velocity
Since we know that if acceleration is 0 then velocity must be constant
e. If an object's speed is constant, then its velocity must be constant.
FALSE
Speed is just the magnitude so we can not say about its direction and hence if speed is constant then velocity may or may not change
<h2>Book will hit the foot with force 21.8 N</h2>
Explanation:
The momentum of any object = m v
here m is the mass of body and v is its velocity
Thus momentum P = 3.2 x 1 = 3.2 kg-m
As the book is falling freely , so it will fall with and acceleration g
The force exerted by it is = m g
Thus force = 2.18 x 10 = 21.8 N
Force, newtons 3rd law of motion stated for every action there is an equal and opposite reaction
Answer:
12.02 m/s north of east
Explanation:
Let be the horizontal and vertical velocity of the 3rd piece, positive in the East and North direction. Also let m be the mass of the 2 smaller pieces, so 2m is the mass of the 3rd piece.
We can solve for the 2 velocities components using law of momentum conservation. Before the explosion, the total momentum was 0 because the coconut was at rest. After the explosion:
- In the x direction:
negative 17 because 1 piece flew west
- In the y direction
negative 17 because 1 piece flew south
So the speed and direction of the 3rd piece is
north of east