Answer:
Explanation:
a )
momentum of baseball before collision
mass x velocity
= .145 x 30.5
= 4.4225 kg m /s
momentum of brick after collision
= 5.75 x 1.1
= 6.325 kg m/s
Applying conservation of momentum
4.4225 + 0 = .145 x v + 6.325 , v is velocity of baseball after collision.
v = - 13.12 m / s
b )
kinetic energy of baseball before collision = 1/2 mv²
= .5 x .145 x 30.5²
= 67.44 J
Total kinetic energy before collision = 67.44 J
c )
kinetic energy of baseball after collision = 1/2 x .145 x 13.12²
= 12.48 J .
kinetic energy of brick after collision
= .5 x 5.75 x 1.1²
= 3.48 J
Total kinetic energy after collision
= 15.96 J
Answer:
The object would weight 63 N on the Earth surface
Explanation:
We can use the general expression for the gravitational force between two objects to solve this problem, considering that in both cases, the mass of the Earth is the same. Notice as well that we know the gravitational force (weight) of the object at 3200 km from the Earth surface, which is (3200 + 6400 = 9600 km) from the center of the Earth:
Now, if the body is on the surface of the Earth, its weight (w) would be:
Now we can divide term by term the two equations above, to cancel out common factors and end up with a simple proportion:
Answer:
1-An object's velocity will change if a net force acts on the object. (True)
2-In order not to slow down, a car moving at a constant velocity needs a small net force applied. (False)
3- The net force which acts on an object which remains at rest is zero. (True)
4- If an object's speed does not change, no net force is acting on the object.(True)
5- If two objects are under the influence of equal forces, they have the same acceleration. (False)
6- During the collision of a car with a large truck, the truck exerts a greater force on the car than the car exerts on the truck.(False) (Newton Third Law)
