Answer:43.7 N
Explanation:
Given
Mass of tennis ball is =57 gm
velocity of ball=21 m/s
The player volleys the ball straight back at 25 m/s(i.e. in opposite of initial direction)
time of contact=0.06 s
We know change in momentum
initial momentum
final momentum
change in momentum
Now 2.622
Inertia: tendency of an object to resist changes in its velocity. An object at rest has zero velocity - and (in the absence of an unbalanced force) will remain with a zero velocity. Such an object will not change its state of motion (i.e., velocity) unless acted upon by an unbalanced force.
The current is
(120v) / (the resistance of the stove in ohms) .
The unit of the current is Amperes.
Answer:
56 J
Explanation:
The following data were obtained from the question:
Energy 1 (E₁) = 7 J
Extention 1 (e₁) = 1.8 cm
Extention 2 (e₂) = 1.8 + 3.6 = 5.4 cm
Energy 2 (E₂) =?
Energy stored in a spring is given by the following equation:
E = ke²
Where E is the energy.
K is the spring constant.
e is the extension.
E = ke²
Divide both side by e²
K = E/e²
Thus,
E₁/e₁² = E₂/e₂²
7/ 1.8² = E₂/ 5.4²
7 / 3.24 = E₂/ 29.16
Cross multiply
3.24 × E₂ = 7 × 29.16
3.24 × E₂ = 204.12
Divide both side by 3.24
E₂ = 204.12 / 3.24
E₂ = 63 J
Thus, the additional energy required can be obtained as follow:
Energy 1 (E₁) = 7 J
Energy 2 (E₂) = 63 J
Additional energy = 63 – 7
Additional energy = 56 J
Answer:
Explanation:
The impulse-momentum theorem states the impulse on an object is equal to the change in momentum of that object. Momentum is given by 
. Since mass is constant, the train's change in momentum is:
(two significant figures).
Impulse is also given as 
, where 
is the average force applied and 
is change in time. Since 
is given as 
, we have the following equation:
(two significant figures).
